Park/Turn Relay Trouble

I am wiring Bosch type, 5 pin relays for my front park/turn lamps on a 1954 Ford car. The car has been converted to 12v and has a 1 wire alternator. What I have done is 3 relays, one for parking lamps, and one each for left and right turn. On all of the relays, I have constant 12v to pin 30, ground on 85, output to lights on 87, and input from firewall on 86. The pin for 87a is not used. What is happening is with the parking lights on, everything works fine. With the light switch off or on headlights, the turn signals work like 4 way flashers when turned L or R, but as this is happening, one light blinks on the high filament and the other on low, switch from L to R and the same but opposite high/low. The bulbs are LED's. If I bypass the relays, all works as it should. I have successfully added relays for my headlights and they operate properly and much improved. The park/turn setup is my second attempt at installing relays. I am at a complete loss. Can someone show me the errors of my ways? Thanks, Dale1954 Ford Crestline

1959 Rambler American

It sounds like your flasher can is load insensitive (ie, suited to LEDs). It sounds like the relays are not wired properly (despite your correct description) but otherwsie - ignoring that bypassing the relays works ok - it sounds like bad filament/LED grounds. You mention high and low - I presume hibeam & lowbeam? Are they also on relays? BTW - if using LEDS for parkers and flashers, I wouldn't bother with relays unless using very low current switches. (Relays often consume more current than the LEDs.) However hi & low beams should usually use relays (even if LEDs).

Perhaps I was a bit confusing in my description. What is happening is when on relays, park lamps on, everything works properly. This is what happens next. When the light switch is off or pulled for headlights, and I turn my left turn on, the left light blinks bright and the right park/turn blinks dim and just the opposite happens on right turn. My mention of high/low was in reference to the park/turn lamps referring to the bright/dim filaments (or however you describe the bright/dim of dual contact LED's. My headlights are Sylvania halogens and always had that dim yellow appearance, but now on relays work better than ever. On the park/turn LED's, I have tried 2 pair, one w/lesser LED's. The results were the same, so I presume all are good. I also rechecked all of the connections and are correct...or at least as I desribed in my original post. My reason for using relays is the wiring in old 6v systems is heavier than modern systems causing a voltage drop. The light switch is also light duty compared to modern switches. When I had the parking lights on and all worked as it should, the LED's were much brighter than when bypassing the relays. Perhaps I should add a second relay and divide the park lamps. I'm open to all suggestions. Thanks, Dale1954 Ford Crestline

1959 Rambler American

Just a comment on relays for 6V systems (it's 6AM and I'll be up for work in 2 hours)... The 6V switches and wiring being heavier means LESS voltage drop - ie, for the same power, 6V distribution (switches & wires) need to handle TWICE the current compared to running 12V. Hence there is less reason to use relays than there was in the original 6V system, though I always suggest relays for headlights - especially halogens since they suffer more dimming than tungstens for a given voltage drop. But I also tend to use relays for any circuit with more than a few Amps (wipers, electric windows, maybe even reverse or stop lights) since that takes the strain of the switches (my vehicle is over 40 years old). I'll think about the behavior you described later....

Thanks again OldSpark....you are very quick with your responses and I appreciate all of your help. The difference in the brightness in using the relays vs not using them is remarkable. Let me know what you think about adding a 4th relay and dividing my parking lamps. Thanks, Dale 1954 Ford Crestline

1959 Rambler American

Shall do. If relays make a difference, that indicates an original high resistance path - eg, long wiring, thin wiring, lots of fuses or connectors, high resistance switches or connectors etc etc. Suffice to say, ignoring switch resistance and fuses, just using the same wire from the battery or alternator or fusebox etc "direct" thru a relay to headlights is usually ~1/3rd the wire length (or less) than the original wiring, hence 1/3rd the voltage drop (or less). (Note - due to that wiring alone.) Not that the original voltage drop may have been that big (noting that 1V to 3V drops are not uncommon in 12V vehicles! ), but usually heavier wire can be and is used, and relays tend to have less contact resistance than switches... IMO reducing halogen voltage drops by 1V can be quite significant. FYI - tho "up to 3V" drops may be considered acceptable to the automotive industry, I usually design for a MAX voltage drop of 0.5V. And that's across the load - ie, the +12V and the GND voltage drops combined. So my halogens run at (say) 14.2V - 0.5V = 13.7V instead of maybe 12.2V or 11.2V.   Now if you get a graph or table of halogen light output versus voltage... Anyhow, it's 41°C outside. I'm heading upriver for a swim.... 4th relay & the rest later....

Summer in January just sounds odd! We did have a nice day today though at 50f in Kansas City.....not bad for January! Watch out for the critters!1954 Ford Crestline

1959 Rambler American

Hey, How about this heat? (Dennis Leary - I'm An donut hole - great song & clip.) Nearly midnite and it's still over 32°C/90°F outside and hotter in here. But hey, it's gonna get down to a nice cool 28C/82F overnite. And what critters? You mean our killers? I was on the lookout for tiger snakes (my girlfriend nearly trod on one last time we were at the same place) but it turned out a submerged tree got me. I haven't seen the river that high for years and I assumed that despite the faster current I'd have better clearance to the rocks as I rode the rapids. But no tiger sharks either, tho it's way too upstream for them. However knowing that Bull sharks live & breed in fresh water, and they're the worst attackers/killers - apart from wasps, bees, crocodiles, and people. And apparently the Koalas died out a few years back (we used to see a few) so I think the drop bears have also gone.

Oh sorry, I lost the plot. Litres (quarter-gallons) of water, lemon cordial (with soda water of course!), lemonade, and more water - even a coldish shower - and I was still lost. However now the 2nd (BIG) glass of gin & tonic seems to be working. Oops - I forgot to hang out my washing... ... delay .... Where was I? Alas I keep thinking poor grounds, but first a few clarifications... You wrote "... or however you describe the bright/dim of dual contact LEDs". Yeah - let's say bright or ok, and dim - just to avoid hi/low beams. But 'dual contact LED' - I presume you mean a normal 2-terminal LED - not dual color LED with 3 contacts/terminals (else polarity reversal to get the other color). Normally that's not an issue, but since you guys tend to have flashing stop lights (as opposed to our separate amber/orange flashers aka indicators) and since now red stops changing to orange flashing might be installed... Else combined flasher-parker LEDs could be yellow/white... So, maybe hence & ignoring headlights, all your lights are equivalent to "single filament" dedicated bulbs - ie, ordinary LEDs - tho each light or LED may be several strings of individual series connected LEDs. If so, let's call each LED assembly or 'bulb' or 'filament' a LED. It shouldn't generally matter. If your left front flasher LED is actually one only CREE LED or one string of 3 supabright LEDs or a few parallel strings of bright LEDs - big deal (unless we get to talking about individual string problems, but ignore that for now!). Only if a 'bulb' acts like 2 separate 'LEDs' as in a dual-filament stop/tail or front flasher/parker need that be clarified (to me). [ FYI - for same colored stop/tail etc, its (usually??) the same LEDs but with one of 2 internal resistors bypassed. ] O-oh - my 3rd G&T. The o-oh is not the Gin, but the last of my chilled Tonic. (I'm living off two 12VDC/230VAC 'camping' fridges. No ice, and limited storage.) Hey man, howz this heat? (Yes, I'm wearing downunder shorts. I need to keep the furniture clean.) And all lights are LEDs - ie, parkers, clearance, license plate, front and rear (& side?) flashers, stop, reverse, emergency flashers, self destruct warning, and get out of my way I'm coming thru warning flashers? Your headlights are halogen. This should not be relevant, but are they H4 hi/low (& maybe additional highs), or separate hi/low halogen bulbs? Your headlights use relays. And your dash flasher light is NOT a SINGLE bulb (2W or 3W) for BOTH flashers (ie, connected between Left & Right flashing +12V signals)? The dash flashers are a LED for each side, else maybe a bulb for each side (it should not matter which). And your flasher LEDs are flashed via relays - ie, your flasher 'can' flashes the relay coils and not the LEDs directly. And so too the dash flashers - ie, all left flashers (front, rear, dash, & side if applicable) are thru one relay, and the RHS thru the other relay. [ As before, IMO the relays should not be necessary. The can and wiring should/could flash the LEDs directly. In fact, use an appropriate flasher-can that uses a chip (integrated circuit = IC) else appropriate circuitry and it should be reprogrammable to hyper-flash if one (main) LED fails. Reprogramming is the changing of one resistor. F.ex, my (new) Isuzu flasher cans use a chip (I think the Amtel U2043B) and I calculated that changing one resistor value means it will sense a LED outage instead of the 'standard' ~21W bulb outages it was originally designed for. That assumes ALL flasher bulbs (including the dash & sides) are LEDs. ] Your parkers are on with beams/headlights. IE - unlike some old vehicles that turn off front parkers when the main beams are on, yours are on all the time - except when the light switch is OFF (d'oh!). (I changed mine - merely reconnect the front parkers to the rear tail lights so they are on all the time.) Your firewall ground... No - it's your 86 from firewall - ie, your in cab +12V control signals go thru the firewall to 86 of the relevant relays. Sorry - I thought you were grounding to the firewall. (Damn gin.) ((No - damned short term memory!)) BTW - good onya for using the conventional 85 GND or 'more -ve' and 86 'more +ve'. That's important when using relays with inbuilt spike suppression diodes (even tho I hate them and prefer to add my own diodes to the harness or relay socket, and they are becoming rare anyhow).    I may tackle grounding later unless you can assure me that the grounding point(s) are suitable - ie, heavy for halogen GNDs, and that common wiring [eg shared LED or relay 85 GNDs to the actual GND {chassis or batt -ve etc} is solid enough]. That may include confirmation that you checked the voltage between batt -ve and the LED's or relay's or halogen GND when device is actually operating - ie, that confirms adequate wire gauge and GOOD bonding to chassis etc. [ So many times a metal to metal contact is no contact at all. VIZ - my severely tightened 24mm/1" bolt that bolted the 2 HEAVY batt -ve & chassis GND cables & lugs to the engine. High resistance caused my (then external regulated) alternator to generate ~16V for body/chassis electrics thereby blowing the front panel display (only) on my beloved Alpine HU. ] Oh boy, I think that'll do. Besides, I'm ready for a 4th gin. (And if I don't add tonic... ) Hopefully I've written the above &@%!%$##! crap so that you can just answer 'yes, as you expected' or as you have written etc. Only the exceptions - or clarifications - need be otherwise mentioned. I hope I haven't tested tolerance or humor. And tho I'd like to make sense, I'm way past hoping for that. (No, that's not the Gin, that's the last score or 3.) And I was happy finally having had my first stand-up nature relief for many hours - until I realised that that should have occurred BEFORE hitting the gin. Hey kiddies - hydrate before alcohol consumption! (Hey, How about this heat?) O oh, lighting. That probably means more bushfires tomorrow - and I'm going bush. (Also o-oh, I just finished a gin with half-warm tonic. Not sure if I type too slow or drink too fast, but I have has distractions. It's now 2AM and 36C outside.) Good (hic) night. (Not that you're a hic.) ...burp

Dale - sorry, I have no recollection of the last 2 replies, and of course once you reply to this I won;t be able to delete them. How did you go - any progress? (Or still too cold?) And not that I addressed your 5th relay question...