Printer Friendly Forum Posts - car battery & system problems,plausible?

Hello again,
This last 2 months my vw t4,7da,swb,pet,2.0lt has been worked on in the garage to find why it won't start. Parts of the ignition were replaced and briefly ran again until it stopped agawork and became the reason it restarted but with added mistakes of compensating for fixed parts therefore adjustments needed.The reason for its non-start is debated in various ways and this one is A most likely.
A new battery is next to go in because the old one is old. But this only means it can't give enough power. Or so I think.......?

Q. Is this old battery likely to have caused damage or create its powerless current in a deformative way system wide, enough to confuse the electrics into a start/stop state?

Clearly it would hold a less powerful command over the electrical system but fluctuating currents in it might hold a devastation unseen.
A typical trend would be in idle the van just shuts off and no spark is given to the spark plugs. But when tests are done they seem operable and most associated parts with the ignition are replaced, eliminating err.
Q. Could it be capable of that.

It has a digifant II electronic injection and immobilizer which all rely on accuracy(and there are many components relying) so every new part increases the likely hood that it will work, but it seems to be getting no where ;WITH information from the ecu(computer) and hands on tests. It all is underlined by the unknown area which causes the problem and not much seems highlighted with broken parts. So it may be from such instances however trivia
I don't mean that it can provide the actual sole reason for all of the problem, rather could the fluctuation of energy vary wildly enough to support a voltage or current 'lightning strike' because internally it is suffering the same.

My electronic mind is limited.
Sorry.

Battery, alternator, low power = battery. Fluctuating power = alternator.
Immobiliser, if faulty well not let you start cannot cut out the engine once running.
Also possible, O2 sensor. That will kill the idle once warm.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Geez those Aussie speak funny...

As per Howie II.

Alternators & batteries should be easy to check. If 'garage' means a mechanic, then she/he should have a DMM (multimeter) and know how to do basic checks. (I know there are some electrically hopeless mechanics out there, but geez man, even in ye olde days one usually had to eliminate electrics as a possible problem. These days it usually a case of send the vehicle to an auto electrician BEFORE sensing it to a mechanic - unless the mechanic has good electrical and sensor testing skills.)

The alternator should be charging above 14V except perhaps at idle or low speed with heavy loading (after cranking with lights & wipers etc on).

A bad battery will dip significantly during cranking - eg, below 9V or 8V.
A fully charged battery should be ~12.7V after it has dissipated surface charge after charging (that can take up to ~24 hours).

Even simple tests like headlight brightness at idle versus revving can confirm electrical issues.

Blimey mate oi couldn't understand what you geezers from the sarfern emisphere are on.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Thanks for the assistance, I used a multimeter to find that the distributors NEW hall sender isn't working. I can't understand what causes the electrical components to stop working or become broken.
As I understand the voltage, if different THEN things become broken but the other ways I have no knowledge of.
As you say alternator would have an influence, but these parts don't work any more. Ignition switch,ignition,ignition transformer coil,distributor hall sender,spark plugs, rotor and cap,idle regulator and battery(Wednesday).

What could be the reason. The batterys MORE responsible than the alternator or the whole vehical isn't earthed.

I've just never heard of electrical failure without component damage or incorrect power sources.
That's OK if you don't understand the situations difficult anyway. Thankyou for your help anyway.

To be honest I've never come across a petrol T series, only diesel.
Having said that they (VAG cars) are notorious for ECU and component such as coil pack failures.
A Hall effect switch with no moving parts? Though having said that I had a cam position sensor fail last year, also a hall effect switch.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Ah - I missed the VAG (VW) part. (2 weeks ago there was a car fire outside my work - I had left early. I asked if it was a continental (ie, Euro) car. Yep - sure enough - a BMW. Geez - what did I know - other than TC Cortinas and Jag XJ-6s tend to be rare these days... posted_image

)

The only thing that should be causing successive electrical failures is overvoltage (ie, alternator goes too high; usually above 16V) else bad connections that cause intermittents, hence thermal fatigue & component failures. (Repetitive bulb failures are usually caused by intermittents. I don't know why people keep blaming "shorts"!)

Halls are less reliable than reluctors but they should be reasonably reliable. As I recall, Siemens HKZ series "vane" Hall modules as widely used for distributors operate to over 20V.

Car & their components can have a design life - especially these days. (The old rule was if you owned a Euro (including UK) car, get rid of it once it starts causing trouble.)

First I'd suggest disconnecting and reconnecting all connectors; rotating same sized fuses; & cleaning battery terminals. IMO that fixes over 90% of electrical problems. Also remove & refit the GND connections from battery- to engine & body/chassis (clean surfaces if they look contaminated; ditto for any fuses or connectors).

Also ensure no engine or engine bay overheating. POST EDIT- and engine or other vibration.

After that I'd suggest taking it to an auto electrician. They should be able to scope (oscilloscope) the DC supply to check for excessive spikes (eg, from fan motors or due to aged batteries that are less at effective absorbing transients).
Mechanics are usually not the solution. Even if they know how to test a fuel pump or use a DMM, they probably don't have scopes etc. Mechanics can however prove very good at blowing ECUs, or replacing every ECU sensor trying to find some running fault. That reminds me - a special thanks to whoever replaced all ECU components in that 1988 Astra at Pinch A Part Kilsyth; I now have a Delco setup for my old engines complete with new sensors - even a brand new HEI module! (I don't use those crappy multi-piece reluctors as used in N13s & Camiras & VN Commodores so its brand new dizzy was otherwise a total waste.)

....over voltage from the alternator, I read somewhere there's a place on it ,symbolized with an "A" that is prone for errors. I'll look over it.

This is my first van/car in over 15years and it was a nice change to be able to get into the vehical via the vagcom, using its capabilities with the injection was a fun component.
Its just silent whilst everything isn't working.. posted_image

old battery multimeter 13.4 VOLTS
posted_image

new battery 12.8 volts

So what's damaged....where should I look for that(eg burned wires, parts that are under par with 13v useage) . I left the charger on and off for three days to get right up to full power and its hidden defect reveals itself, what did you say...thermal fatigue & component failure, intermittents....to what extent will this penetrate the system, HAS penetrated?

Already the new $130 hall sender won't supply the spark posted_image

. Replaced no30 relay and will have to get the components again! Test and trace for only weaker parts, which will fall? Which ones would/could sustain the overvoltage if any, it could save some money in replacement parts.

The alternator needs a test output value could you enlighten me please.

The old battery must have been after a charge with residual surface charge. A 12V lead acid battery cannot be more than 12.7V (with few exceptions).

Car components will handle 14V since normal long-term charging voltages are usually up to 14.4V.
The usual spec for (automotive) 12V equipment is up to 16V.

And fuses should blow before any wiring melts - that's what they are there for.
There are some exceptions like the heavy starter motor cable; ignition (coil) on older vehicles, and any unfused wire leading to a fuse.

Hall senders (ie, sensors or modules) only supply a signal to the ECU ot IgCoil ignitor. (Reluctors are the only sensor modules with inbuilt ignitors tho some are sensor only that feed ECUs or external ignitors etc.)
Have you checked the IgCoil?

The alternator should charge at up to 14.4V though some may exceed that after initial startup.
Modern 12V vehicles are usually set to 14.4V else 14.2V. 13.8V was the old set point but that is too low for modern batteries and prolonged battery life.
Alternators may be lower than 14V etc at idle or low RPM with heavy loading - eg. lights & wipers - but should return to ~14V at normal RPM.
Some newer alternators will drop to ~mid 13V when the battery is fully charged. Some assume full charge after some delay (say 10 - 60 minutes) or when the alternator reaches a certain temperature.
Alternators often vary output voltage with temperature since bater charge voltages vary with temperature.
I mention the above exceptions in case the typical 14.2V - 14.4V is not observed so you realise it might not be a fault.

....?

So where do the dead parts come from, ecu gives them wrong voltage?
I don't understand what the problem is. The entire ignition system is replaced with new parts, now after 1 test drive it has the same symptom's and I'm yet to test them, broken elec components.

I get at least readings of current to them and at ignition, but its stopped at the hall sender (again). Brand new it sent a strong spark when the key turned to ON, I could then start the vehical for tests. The next thing is a low idle (idle regulator new) which is probably an o2, air sensor; this stalled the vehical. The ecu IS compensating whilst tuning...good, but the individual elec parts are being knocked out via..something. This is essentially the problem. Unless there is some way the ecu is able to ..? then there's no other option that I can see!
The coil new, might have sent a bad current to the new hall sender and survived it but all in all its the only reasonable explanation I can find. Earths are large cables, checked.

How are you testing the sensor?
How do you know it is not an ignitor or IgCoil or wiring or connector breakdown?
You know it is a failure of spark and not fuel/injectors?
Is it a 5V sensor and is it getting 5V or more than 5.5V etc?

And your alternator never exceeds (say) 15V nor do your car electrics? (Ground faults can cause voltage differences of several volts. That can cause voltages above 16V - especially on vehicles with external body/chassis mounted voltage regulators.)

Have you checked the alternator for shorted diodes that pass -ve voltage, or open diodes?

I suggest taking it to an auto electrician. IMO that will cheaper and your simplest option.

I would venture to suggest that inexperience is causing you to go over the top in testing and draw the wrong conclusions.
An experienced auto electrician might well have come across your problems before, know the answer and sort it out immediately.
Out of interest two things come to mind instantly apart from the aforementioned alternator.
Bad grounds (earths) have been a particular VW problem since the early 80s.
Substituting cheap cheap coil plugs and causing grief.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

I agree.
Mostly testing connectors as the info on sensors WAS on my tablet but it got switched off before I could read and apply, now its just memory. Which is one of the tests, the current from the battery, through to the component has this one reading for current and others have differing voltages for their specific use, usually less but an info sheets required for those.
Basically the vacume/digifant systems, current/battery, mechanical parts and general servicing and cleanliness are being tended until the problems found. The advice brought by forums helps find ways to fix quicker but not always right so this forums question was why a 'short' could make a difference, surprise, its not as direct as a bad battery. Thanks fellas. posted_image

As the score is .
Everything I poke a stick at has an answer. The problems have other factors of cause. Nothing I've fixed has any reflection/asscociation of the next problem fixed. The tests from ecu show everything is in order. Forum tricks get applied anyway and I'm running out of reasons why I can't Start the van with no where else to turn.

No power seen from the new hall sender. Something's blown it up, but the currents path to it didn't blow up the rest of the new components. ??

Checking starter motor. Can back flow.
Checking solonoid for coal filter, zero v reading.
Replacing hall sender, and it will start after...but I won't risk blowing that one up $130 a pop.

Eg tests. Ignition ON. Battery 12.7
To coil 12.5
Coil lead to dizzy 12.4
ICV 12.6
Air flow 5.0
Throttle 5.1,4.6,0
Blue 5.1
Black 12.5,0.2,0
Etc

You say current testing which worries me. But I presume you mean voltage. (Essentially current is irrelevant - unless a fuse blows or heat/smoke occur.)

Some sensor supply voltages may be 5V (usually +/- 0.5V) - eg, AFM, MAP etc but have varying signal voltages or even have 'digital' (pulsed) outputs.
Others vary eg - temp.
What signifies correct operation usually requires datasheets and specific test conditions.

The behaviour of some sensors depend on the type. EG - a reluctor module will only output whilst rotating (usually a pulse).
A Hall Effect module should be low or high (or rather, grounded else floating unless pulled up to 5V or 12V via a resistor etc) but a Hall Effect ignitor (like a reluctor or any ignitor - EXCLUDING CDI and some systems) should only pulse low for a brief time - usually less than 10mS.

And you should NEVER read the voltage (or resistance) of some sensors - eg, O2 sensor elements - as that will destroy the sensor (or trigger airbags etc).

Take it to an auto electrician.
Otherwise search VW and other forums for the specific detail you need.

Yes, later I'm might be able to find exactly how to TEST parts. Now is just to find bad wires, wrong readings (its all I can do anyway!) Just enough to try out the ecu, if it is at fault-if not that only leaves the alternator. All fuses checked, earths cleaned etc.

Testing the hall sender;
I've no idea how to, maybe with tiny instruments. Thanks for the volt guages. Essentially the hall sender can't be a major blame of not working from what your saying, its finer role is Dependant on volts/ecu and functioning vehical. It is just the way I'm getting it fixed. But what ever blew it up twice is ...... A bleep!
This new ones gone (and now that I think of it in much the same circumstances) but I haven't tested it, just a volt check 0. Both times the vehical is (low)idling and the van just stops. The senders just don't work after. I got the impression the earth just failed.
The starter motors off and its got damage with cogs, solenoid needs a test....and the alternator when working.

My whole guess is it is some sensors, unclean connections, unseviced parts, leading to bad timing and compensated by the ecu thus things go wrong. Elecs need the experts.

The voltages you posted look fine to me. Not that I know what Blue & Black refer to, but the the others look fine depending on the situation.

Like I said, the alternator is easy to test unless it has faulty diodes.

If it's stalling at idle, are you sure the idle speed is high enough, or that the battery and its connections are good?
Idle speed should be easy to adjust.

If it's bad timing, adjust it. That;s not a bad sensor issue unless it is erratic.
But bad timing won't blow components - it will only blow the engine.

I should elaborate, it runs(ran) rough with an intermittent dip, almost stalls, every 10sec. I replaced the idle reg and removed that but it still hits a spot and trips over itself, so it defenitly needs timing and sensors replacing to give the ecu time to find the right fuel injection and idle speed(currently too low,erratic).
The battery's new....just keep fixing things till nothings on list.
Just rementioning the strong spark at ignition ON only, I was thinking maybe a fuse could've let that in?! To think a working engine gets one of those at the some time, the flux would burn something out.
..fuse or exposed wire..or....

So you've checked the fuel pump & filter and its pressure? And the air filter?
And compression, timing, splugs, & valve timing & clearances?

Injectors have been cleaned?

Strong spark at IGN ON. Do you mean when you first turn on the ignition. That should not happen. If the ECU controls the spark, then it's likely to be a faulty ECU. Else it's some contamination (shorting wires etc) or a failed ignitor etc component.

That sounds like it... Yep the first time I tried with all new ignition line up the test of sparky1 was out to see function, so because I've only got one set of arms, I recorded the event..there's a sec from turning the key and zap. I've checked its earth..had it out to clean,clean as...electrical function. I can send it off for return in a flash.

I can't do valves etc just haven't got those tools yet.

Could you possibly surmise where a voltage spike may emanate from?
The suggestion the hall sender damage was from one seems likely as this description suggests.
...Hall Sender works by creating a signal as the shaft of the dizzy spins. It feeds a signal back to the ECU telling it which cylinder is approaching the TDC position and the ECU then uses that information to trigger a host of actions at that moment in time.

Hall Sensors are usually quite reliable (hence the reason they were used) but we do know that they fail due to age (they start to physically break into pieces inside the dizzy). They can also be damaged by voltage spikes, a classic example being when someone takes all the spark plugs out and spins the engine without grounding the king lead from the coil (HT lead). A visual inspection might show physical damage inside the dizzy itself?.....

In some effort to rule out this and at the same time get the immo/ecu checked.
Where a spike could be from.

As aforementioned, bad grounds, batteries, connections...

Otherwise usually relays and other inductive components (motors, IgCoils, etc).

As to ungrounded splugs causing damage, I doubt it though they can damage ignitors - or could in older vehicles.

If it is a hall sensor that feeds the ECU, such a spike would have to go from the IgCoil thru the ignitor thru the EU to the hall sensor.
But systems like Delco have the sensor circuitry and ignitor in one package which also handles the ECU supplied timing signals. But they afaik use reluctors, not Halls.

So is your "Hall Sensor" a sensor module only, or include the ignitor (that feeds the IgCoil?

Known problems on that engine:-
Petrol: Poor quality coil packs, prone to none starting.
Diesel: Dual mass flywheel breaks, causing clutch damage. Fuel pumps and injectors fail.
Both: Transmission (auto) failure.
Endemic amongst ALL VAG types; ECU failure.
Check with "honestjohn" UK.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Thanks...the likelihood of more than one thing wrong IS more likely. My van from ecu is to transformer(coil) then hall sender, AND the ecu is supposedly good! value rarely bad...speculation is wild. So far with all the new replacements and sensors that could be bad I am no closer to really knowing what its exact problem is.
Hopefully this is the last of it. Alternators been out and waiting to be multi tested, brushes good...

What makes you say "the ecu is supposedly good" (& rarely bad)?
And who is telling you this?

IMO it's obviously more than one issue unless it is the ECU as I have previously mentioned (assuming sensor-ECU-ignitor).
If it is, the only guaranteed fix is to swap ALL relevant parts. I usually recommend that instead of buying another working model of the same and swapping battery, alternators, all wiring looms & all electrics that they simply keep the "new" working vehicle and scrap the old.

People used to do the old external alternator-regulator runaround - ie, replace what they thought was faulty (eg, alternator) only to find it was the regulator so they replace that but find the faulty regulator blew the alternator so they replace both only to find it was a bad ground to the regulator that caused the problem in the first place - so THREE sets of new alternator & regulator are expended to fix a SIMPLE connection problem. (The irony being that if they instead replaced the older external regulator system with a new integral type, they won't have that problem; they'll have simpler and cheaper future repairs, and they'll enjoy far superior alternator/electrical performance - & probably with higher alternator capability.)

Now if such a simple "free fix" alternator problem causes so much time & expense, imagine such a novice with an entire computerised multiwire multiconnector multi-peripheral system! (Blown OC transistor in the A09 address line? LOL!)

DIY repairers are usually the best friend of industry repairers and parts suppliers - the expanded or repeated damage or expense by DIYers often outweighs the loss professionals have due to competent DIYers.
But I commend your exploits. It's nice to have the unessential vehicle and budget to be able to DIY fault find using trial & error. (Tho I admit I'll usually research - sometimes due to laziness, but usually because I hate waste - & prefer to spend my money or time elsewhere. Besides, I'd probably want to DIY replace rather than DIY fix something that IMO is inferior of prone to problems or subperformance.)

Nice post Peter and did mention poor earths on Mkl and Mkll Golfs, transporters etc.
OP make sure you have good clean corrosion less connectors.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Yes, the bones of it in simple checking for me.
Most info comes from trawling the net and the post said its "uncommon for the ecu to go, more durable than ..." another car.I remember that one, said it was more likely the hall sender etc. this problem wraps itself around other similar problems so I dismissed it and got new parts.
I've just ordered in the air flow sensor because a post identified it to be the reason for erratic idle, but the test for it gave vagcom the hand to see it drop in temperature when a substance drove the temp lower, then watch it rise, it showed it works! but without doubt if it errs then the ecu errs and sends erred info about- this is also the lambda o2 area, so assumingly the REALLY the broken part, until later I change the coolant sensor which contributes to the same problem..differently, leading to errors from reading sensors, from ecu. A circle of it.
Today the new hall sender arrives and many more days of testing before I even start it. Will get back if some electrical info is needed.
Thanks.

Yes well, "they" are contradicting us aren't they?
And tho you may get tips. you still have to check (see my last reply - and was it this thread where I thanked whoever replaced ALL ECU peripherals (including the complete distributor!) so I could grab them all at ridiculous prices when the car hit the wreckers? A few $hundred worth for well under $100 - and that included the wiring loom. (Why do people spend $thousands of aftermarket EMS systems when they can have a complete and most often superior set up for a few $hundred?}.)

Idle could be the idle air motor (if fitted) as well as manifold temperature and all pressure sensors, plus fuel pressure & pump, dirty injectors or fuel or air filters, valves or clearances, splugs, etc etc. But I'm merely repeating the same old info...

I won't be able to help you further. Except for an in person visit, I've given all I can.
Like I said, take it to an auto electrician. Or if you really want to DIY, then do a proper analysis and determine the problem before buying parts.

An update, the single pole trigger only gives 0.14v when key turned on and ignition on it just stays, the 'cleaned' starter motor won't work now, did have clicks from the relays when turning the key so I re-tuned the position of the magnets to central position for better rotation and now it won't click anything. It should be 12.7v. I guess its somewhere from fuse/relay,immo,ecu and wires. Replaced ignition switch ,30relay, fuses look good....would immo or ecu be responsible for varying voltage?
There are so many posts that contradict but I just sort which is more viable.

Agreed. I've said "find" before buying.
Halls don't burn - if an HKZ type only a voltage higher than 5.5V or excess current going thru its Open Collector output transistor can burn it. But that should be "simple knowledge" with a bit of research & understanding.

I'll umwatch this thread. As I wrote earlier, there is nothing else I can offer (other than a complete course - unless enough specific details are supplied).

Clicking suggests a weak battery. Check its voltage during cranking. It should preferably stay above 10V but some may dip further. Less than 9V usually won't cut it (except for reduction starters).

It could also be a starter jam - whether in the ring-gear (if the starter engages) or the brushes or commutator are faulty.

The 0.14V could be the natural bias/output from the Hall module. But it should swing high (eg, up to 5V; above 2-3V) upon rotation.

If you mean system voltage, for the immo or ecu to be responsible for varying voltage it'd have to be one heck of a fault.
If you mean to the sensor etc, then as before, yes.

Agreed.
The only way an HKZ hall sensor can burn is if its supply is above 5.5V or its Open Collector output sinks excess current. (Bad GND should merely make it inoperative.) But that should be easy knowledge with a bit of research.

But I'm unwatching this thread. As I wrote earlier, there is nothing else I can offer (other than a full course - unless enough specifics are supplied).

Interesting that my reply to Howard's appears earlier than the above reply.
Sorry for the replication, but I thought my submit went bad...

Well it won't give the vital readings required from the part, so its got to be found before it burns another hall sender, I'm off to that.
Thanks.

Jumping to conclusions?
Clutching at straws?
Sensors corrosion and poor grounds, experience not testing everything in sight.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Ha..
All the above correct. I have no blinking clue what fries elec parts JUST turning the key...who would..worse than clutching at straws..strands of live wires.
I am testing with information as I go, where I can, but the results only prove that they give the right result or they're broken and lead to other working parts which makes finding it harder.
The wire brushed connections new parts and good battery have given me solace that it cannot be through negligence, but I can't guess anymore what it might be because it could only be a fused fuse, which you haven't suggested. So...wheres the fried rat in the circuits?

Checking the fuses with a meter is always the first step, it's a given, unfortunately people like Oldie and myself forget we're not talking to pros.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Funny you should say ,checking fuses, I'm just learning how to. Board then fuse. So far its tacky. "A current is present" type of instruction.
I'm going to disconnect the immobilizer, I asked on another post and got quick remove instructions for it. Big job. That will eliminate a major part of any error and reduce looking for points when an auto electrician gets involved...because there won't be any where else to look soon.

Pull each fuse one at a time, check continuity using a DMM.
DO NOT REMOVE FACTORY IMMOBILISER!!
It sends a data signal to the ECU to start the car, removing without access to a VW dealer diagnostic will disable starting completely, only serviceable or turned off via a dealer!
If aftermarket by all means a bad solder joint on it's ignition output is probably a root cause of your grief.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Oh I've been advised step by step instruction. And I could option one of those replacement bypass immo's on evilbay. Either way its coming out, I think anything that has the amount of control those two have isn't meant to be especially when the van can't compensate for one breaking down and can't diagnosis it !?!. S.t.r.a.n.g.e auto.
Yes, lots of warnings about errors from unsurgical removals.

Can't take this any further, removing the OEM immobiliser without dealer level or locksmith level 3 diagnostics?
You've been warned!!

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

One day I might put in another or beef up with alarm system but for now the cost of replacement parts overwhelms me.
You've got threads on it yourselves! but don't have to worry with this one, I just can't find the source of the problem.

OK I'm back and with some interesting .....things. First, the problem seems (after much tinkering) the starter is the main contributor in a earthing catastrophe with that broken planetary cup allowing the inside motor to touch the rest of the housing..what a stupid design!. Not a warped ecu/immo.
Anyway this last enquiry is about such electrical discharges running through connected, presumably earthed areas !? Now with a positive charge. Can the engine, not with a capability to function as an earthing point ,really transfer the current EFFICIENTLY around a large coverage to get into places that I should look to replace because it no longer functioned that way?
I can't add much as it seems to me the main bulk of the car couldn't be able to reverse the flow if a direct link to the battery is instead of its capacity to earth, but that's why I've asked, to be sure...as most of the dead electric parts piles up. Could it sustain against it?

Well the number of times we stress the need for good earths... Bad power earths can destroy equipment via alternate paths, or from overvoltage (especially with externally regulated alternators) and are often the cause of erratic behaviour - eg, no light when both (single bulb) tails & brake are on.
I have often given examples of how metal to metal may not conduct well, or how often extra engine to body earths are added.
But if your starter cranks then your engine to battery earth should be ok for other loads assuming a good engine-body earth (especially if the batt- goes direct to the engine and then to the body) but reduction starters may operate well below 6V (eg, a 0.1 Ohm path resistance).
You have to check the earth voltage drops under load (eg, when cranking to test battery to engine, and with full beams etc for battery to body/chassis).

I did say your starter could be jamming. Starter shorts behave similarly but I expected that to have been noted or checked when your starter motor was cleaned.

I don't know what you mean by reversing current flows. Good earths and bonding are not diodic.

I guess it must be fun having all those parts piling up? But I cannot support that sort of wastage nor potential destruction. Either learn about automotive electrics or take it to an auto electrician and spend your money on better things.

X 2 with Peter, you're over analysing and missing something obvious and simple.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Well your around the right area but I cannot see the physical relation.
eg. Exactly as a relay 'shorted' fused open and can never work correctly again yet works enough to allow current through, it shows exactly those elements that power begins flowing but is stopped at that relay, where a "cross current" occurs somewhere to arc against the whole van. Like you i assume the earths or asscociated. A lot of clicking occurs when turning the key, then they don't after some tries.
No electrical burning smells, physical blackening, sparks sounds or feeling electricity shocking from metal.
So if the circuit remains open to the earthing system what connected areas will (or rather how much to a degree of effect) fluctuate because they're connected to the frame effected.
The starter works now its aligned but when connected won't turn at all.
So...at least the shop will have cleaned parts to work with.

Clicking is bad battery, bad contacts or wires, or faulty starter.
The starter has no fuse and its solenoid supplies +12V to the motor windings as well as augmenting the solenoid (key switch) +12V.
So you have heavy +12V to it and when you connect its solenoid +12V it does not turn?

Any sustained arc is a fault. Replace arcing relays - they are faulty. Switching off stuff does not result in short-sustaining arcs. Isolate things till you find where the arc is.

Guess so. .... The starter just needed aligning when the new planetary cup went in, wire brushed all connectives so it has very little excuse for no function. Mysterious.

Wiring.

Could the ecu have something to do with this?
Unless the large disturbance is from a different place, arcs the earth creating the same problem 'TO' the starter motor!
What's that large..?

A reversed pole.
A crossed wire or cable.

Take the starter out of the car and test it.

OK..to wrap up the immo was sorted by REPLACING it which is legal and the starter works. The problem was traced back to the pin which inserts from the ignition barrel and ignition switch, the pin can't poke far enough into the groove its meant for .... how about that. Why that is, IS beyond me, but now I start it with a screw driver because it may be the reason for fluctuations. Its poping on and off at random at full key insertion (whereas before it wasn't in far enough) so starting was hidden behind this guise. I guess responsible for it.....
Thanks for the assistance (I might try an out of town garage next time it gets this weird again!.)

custum wrote:

I might try an out of town garage next time it gets this weird again!

NO!!! As some wise dude said on page 1, an auto electrician - not some bluddy mechanic.

That was suggested in the same (early) reply as the possibility of intermittent connection, and advice to break and make all involved connections.
After that comes systematic checking - like jumping wires or switches, or testing voltages (usually with a test lamp to provide some load).
Faulty ignition power should have been found quite quickly. (... by a clever person or auto electrician - but not mechanics that can't diagnose a bad battery connection after 3 weeks...)

I sympathize and agree, but I was joking- I'd never see THEM.
Had I found a link between ignition switch, starter motor and hall sender AND went to an auto electrician (and what dim person wouldn't!) to test the many hall senders for a working one, HE said 'to go to the mechanics' as they use the computer equipment related to these types of things,(mainly referring to my van prob) he in fact couldn't test them (professionally), only ohms test with difficulty. He did get readings from them; alas they don't work!, but all in all a busted planetary gear in the starter was the only REAL damage to blame.
I guess there's something there for all of us.
I get another hall sender this week so it will really resolve the replaced parts I ordered in which was basically they entire ignition system, but they had to be serviced anyway due to the years of nowt. Will go to them if it goes though.
Fingers crossed!.

I still don't see why the hall sensors keep failing. If it was intermittent (IGN) contact I can imagine ECU damage (as did the aforementioned mechanic that eventually blew the ECU from repeated trial&error testing having totally missed the problem - bad battery terminal connections), but the Hall should be buffered thru the ECU.
Even bad vehicle grounds should not cause damage thru alternate paths (cables, signal ground wires) as Halls are (always?) isolated from chassis.

And I would have expected an autoelec to simply rotate the dizzy or slide some ferro-metal thru the Hall slot (or magnet past a non-vane sensor) with a 5V supply to a vane Hall sensor, and then check the output with a DMM (resistance) else rig a 12V test light or load. (They should respond to vane slots else magnets; the short "dwells" of (say_ 6-9mSecs being done by ignitors or the ECU.
But I have known of bad autoelecs. However bad mechanics fixing electrical related problems seem to be greater in abundance. And since modern car faults are often electrical, autoelects are a better first bet. And IMO electrical faults have to be discounted before chasing mechanical or "performance" problems, tho mechanical failures themselves (timing, compression, bearings, pumps, leaks, even splugs) should be reasonably obvious.

......welcome to my bad circus show......!!):)

The plausibility you've mentioned about the ecu causing it IS suspected but I don't know how to relate it, yet I was sure the immo had a lot to do with it, and then the odd out of place things seem more the culprit's than the suspects....whatever it is/was can be identified with a culmination of the little wrong things making one large wrong .. to the normal operation of the vehical. The ecu reading it, and compensating for it, adjusting the normal setting too far. A mechanics job.

Once upon a time i considered car battery's 24v, now I know they're 12v but that is as far as I go electrically.

Nah... ECUs are from that selfish part of society - they might cause the engine to blow, but not their own sensors and attachments.

Exceptions (to the latter) are if components break down - eg an ECU resistor shorts (ha!) or moisture bypasses it so the Hall (Hell?) sensor output transistor blows thru over current, or its 5V regulation to the Hell sensor fails.

Even blowing the engine is difficult. The EMS will probably sense faulty injectors that can hole pistons & burn valves (thru lean-out) etc.
In fact the latter reminds me of a common modern scam where people sell components to enrich or lean fuel mixtures. I thought that was long dead but last year I saw a 2011 edition of Trucks! or similar that used the old resistor in AFM or MAP sensor line to increase the performance of the engine by tricking the ECU into supplying more fuel except that they were using an LM317 voltage regulator. Of course that is total crap and I found that its website's info on DIY had been removed. However when searching I found many "recent" sites proposing the same crap.
And its lucky it doesn't work... It seems many have used it to REDUCE the fuel supplies and if it did work, many engines would blow due to excessively lean mixtures.
I don't know if such proposers are merely idiots or ignorants that do not confirm results, or if they make money selling the parts (eg, a 5c resistor or $2 317 circuit for handfuls of dollars) or if they hope the industry makes money from the damage. It's another modern equivalent of mechanics kinking oil-pressure lines (to increase oil pressure for increased performance engines - ha ha!) or draining carbies if not using vehicles for extended periods. The repairs for those tricks made good money for mechanics. (If your kinked oil-line engine survived, it proved that oil pressure is largely irrelevant or that higher output engines work well with lower oil pressure at the bearings.)
If people are silly enough to think that merely fitting bigger injectors means more power, I guess they'll easily be sucked in to hose scams. (It was bad enough when people fitted excessively large carbies - it wasn't until they tested that they'd fine the worse fuel consumption with LESS engine performance. Of course we'd see the black exhaust fumes. And bikes removing exhaust baffles...)

Isn't it place a block of steel in the engine to boost pressure??
All I remember was when fuel injection first came out we were told to remember that the injectors were coupled with electronic management (and the other alternative of just injection...or something) so any alternative wasn't going to be because of this. Placed on the wall around the 80s and many grumbles were heard as out went the 'good system'.
I just learned from the 'VW man' today my ecu can be remapped (sure just basically, but when I get a turbo an upper hand on the item is all you need) AND that my blown hall sensors are from the No30 relay. Already replaced I got another. The ecu WOULDNT account for the damage.
So the system is largely maintanence free as far as im concerned, good as is.

custum wrote:

Isn't it place a block of steel in the engine to boost pressure??

I've heard some tall ones, but not that one (like how tf would it?).
Nah - engine oil pressure is determined by the big end bearings.

Hall sensors do not require a relay. From what I understand, the No 30 relay (pn 165 906 381) is the ECU relay meaning it supplies power to the ECU. It's a 5-pin relay which is essentially a normal 4 pin SPST with an extra output 86a being 86 via a diode. (Why not simply wire the diode externally?)

If relay 30 supplies the Hall, what provides the 5V required for the Hall? (Or is it NOT a 5V Hall sensor?)

If I had the wiring diagram I could confirm the above.

And yes, because of O2 sensor or equivalent feedback, changing sensor air flow & pressure or temperature signals will not effect performance. Same with injectors - UNLESS the original injectors are undersized.
Remapping is required along with the need to change the O2 sensor target (assuming it's wideband) or ignoring the O2 sensor altogether and relying solely on air/fuel mappings.

Well now I've got 2 stories.
The ecu is still suspected !!! Its got clean earths !!!, so what else is going to pull the volts to the hall sender. It can't. The relay (apparently) blew up from decay, the ecu can't send volts. The ignition switch and starter were the only 'bent' parts to note....I hope it doesn't kill this new hall sender. Well see when the things blow up this time in the of order.
I can't picture were the problems from the two versions because it ran WITH these problems, fix one thing and another needs....

What do you mean the ECU can't send volts? If it's not supplying power to the Hall sensor (as I think it does), then it's faulty. But then the ignition won't work at all (no Hall signal). Of course if it's not an HKZ type of Hall or some other 5V sensor, or it gets its 5V from another source, then my comment is invalid.

Ignition switches and starters won't kill Halls. Surges or intermittents might kill the ECU, but not the Hall. (Again, assuming the Hall is powered from - and signals to - the ECU.)

No, I mean it can't overvoltage...the vw guy said it wasn't the ecu giving the volts its the (dead) relay allowing it. Isnt there a resistor or something or not enough power to the sender?

So he's saying it's a relay that supplies power to the Hall sensor? So it's a 12V (say 8-16V) sensor? I wonder what type it is? And which relay supplies 12V to the ECU?

If it's a 5V sensor, a voltage regulator is required, not a resistor. It could be a resistor-Zenor (diode) regulator, but why bother with that when an ECU has a proper 5V regulator?

..well that's interesting but I think my question to him was about 'what shorted the sensor out' and he would've replied in a sense that the parts involved being that an ecu and immo and starter aren't capable of producing the problem I'm experiencing, so I asked what killed the relay and he said 'decayed'. What caused the ecu to kill the hall sender, it can't. So "I" looked over the vehical and found the smashed planetary, maybe its grazed motor on the (magnets) outer case caused the elecy surge at starting, I also changed every elecy part that might pass or be broken by an over voltage and the similar question ALSO relates toward a cause for it, but this side of it suggests it was starter that blew up the sensor via a surge through the system. Probably killing the entire thing for all I know. Just because 1 relay was on its way out is purely coincidental but not out of the question, Normally; but the right answer stems from a car parts capability to inflict a surge. the vw mans advice is right, but I'd start with what's broken and relate from everyone's advice. It just needs 'Twisting' to be from a surge from a starter motor which works regardless and how another part 'could' transmit voltage through to other parts. As well as individually.
The ecu will now go for testing, although your advice seems to base itself on 5-7v capability only...but I don't know. I guess if its connected then its broken!.
My van the circus.

Also I can't say the starter caused it because evidence of black scorching wasn't there indicating arc. It was just the only visible thing broken.

The ECU operates off the vehicle's +12V.

Relays fail. Various reasons. But simple to check, else replace with compatible relay (eg, SPDT instead of SPST; normal relays as emergency for tachometric VAG 5-pin Fuel Pump relays.

So the Hall sensor is protected from external connection to +12V or GND, or it is supplied from 12V and its output to the ECU (usually GND, occasionally +5V or similar) has ECU-to-Hall protection, or...
Cool. I'd like to see the relevant wiring diagrams...

"Failure" surges are unlikely to be an issue since surges above 200V are considered normal anyway. IMO any "automotive" 12V device should (typically) tolerate 16V in addition to spikes of (typically) 400V - or higher. Critical or expensive automotive +12V systems must allow for such norms. Most automotive equipment meet or exceeds such norms.

Tho Starter Motor faults are not the norm, their spikes are usually not much higher than common relay spikes. It's more likely resultant voltage dips that cause problems like "brownout" damage or overcurrent damage to the battery & wiring. Power cycling & intermittents can cause arcs or blow equipment.
But a big spike blows insufficient protection. Inductive and digital circuits tend to be far more prone to failure (keep Power cycling your PC or batteryless laptop on & off...). Analog components & circuits usually fare better.

Whatever it is has got me, 4-5 hall sender's at $130 each....that's no good.
Checked the loom, no burned wire. There was a 4 way join with other parts on brown wires, which enter the cab. I thought of separating the dizzy link but I'm not sure what's in the cab.
Ecu gets sent off for a week in the Bahamas.
Heres an exact symptom..the key turns and the starter cranks over for a good 45 secs and start stalls. Try again and no start. There isn't another chance as the hall sender is now dead.
??who knows.

The Hall sensor has nothing to do with cranking - unless some cranking limiter or (post start) cutout is involved.

45 seconds of cranking can be enough to discharge some batteries tho reasonable self- recovery (SOC or reserve power increase) often then applies.

I guess its the ecu then. One blown transistor allows over voltage (joking), or the vehical poles are reversed.
Got the new sender, will let you know. Is there such a thing as a 'too cheap' sender?.

Forget about hypothetical causes - it could be a nearby transmitter (which IMO is more likely than others reasons given) - FIND IT.
But IMO the info you have been given is wrong and I'd need wiring diagrams else component information or respected qualification to think otherwise. But with my experiential probabilities in mind, in absence of further into, if any reader wants to place bets...

Of course if Mr VW is correct, it can't be the ECU (blowing the Hall) can it? And replacing the (Hall) relay will solve the problem...