Printer Friendly Forum Posts - smoke, fire, what happened?

`88 Mustang(Auto), Ultra Start 3285

https://www.ultrastarters.com/products/3285_XRPRO.html

https://www.ultrastarters.com/manuals.html

I hooked up the remote start and it works great. Went and got two relays to be able to remotely open the driver door lock.

I'm under the impression this is the correct diagram from the manual for this model vehicle and style locks?

# 30 is ground right? One thing I did was daisy chained the grounds together, and the positives together.

There are only so many wires coming out of the door so I am near certain I got the right two as there weren't any "maybe it's that one".

I hooked it up, pressed the unlock button, remote played music, heard usual noises from remote start box, then the hot wire going to the relays starts to smoke and catches fire. Unhooked it.

Everything appears to still work.

Did the unlock part of the box likely get cooked? How can I test to see if it's still good?

What likely happened?

Your images do not work. 30 is definitely not ground. You need to cut the factory lock wires in the car. One side goes to 30, the other side goes to 87a. 87 and 86 get constant power, 85 gets the (-) trigger from the Ultrastart. You do not ground anything.

You need to be testing wires with a meter, not just hooking up wires that "look right".
Twist the factory wires back together and make sure your door locks still work. Find the wire you think is "lock". It should jump to about 12v when you hit lock on the door switch. Cut that wire. Put your meter to one side of the cut wire. Hold "lock" on the door (the door locks should not do anything). Did the meter jump to +12v? If yes, connect it to 87a of your lock relay. If not, connect it to 30. Test the other half of the cut wire, it will test the opposite. Connect 87 and 86 to FUSED constant power. A 10 amp fuse will be fine. 85 to the "lock" output of the Ultrastart.

Repeat for the unlock wire, using a different relay of course.

Direct link to it: https://img145.imageshack.us/img145/2091/wirezm7.jpg

The diagram makes perfect sense to me now after you explained it. Thanks very much.

I used T-Taps so I didn't have to butcher the wiring so nothing is cut and the factory locks still work. I just wonder if the ultra start is fine? Could it survive that?

I had the relays getting power from the yellow wire in the column. I had a 16 gauge wire connecting them to the power.

So basically the relays hooked that hot wire to ground and starting draining the battery the way I had it hooked up?

I'll get two fresh relays and try again. Still wish I could test the module to make sure it's ok. I suppose it should be..

Also my relay wire job looked insane and amature. How can it be wired up clean considering all the power hook ups?

Some thoughts:

The factory door lock wires MUST be cut to interface with them properly. They are grounded through the switch when at rest, and if you send 12 volts to them without cutting you've just created a direct short circuit. Get over any hangup you have about cutting factory wiring, because it's necessary in this and many other cases.

Your brain is probably fine as long as you didn't connect its unlock/lock outputs directly to any factory wiring.

T-taps are a poor method of connection. Use butt crimp connectors or strip a bit of the insulation back and solder the wires together.

Your relays are probably fine - it sounds like all you did was cause the short circuit mentioned above, which would indeed start smoking.

As JWorm mentions, the 12 volt input for your relays must be fused.

For clean looking relays the easiest option is to buy them with harnesses. If you've had to use individual spade terminals that's fine, wrap each terminal with tape on the outside and then wrap all 5 wires as a group.

-------------
C Renner's Auto Electronix
My service is cheap, quick, and good - pick any two

Smoke, fire, what happened..... A very eye catching subject.... posted_image

-------------

The situation went from that initial close call to bad. It's worse off now then it was.

I got two fresh relays as I didn't trust those first two after what they'd been through.

I wired it up exactly like the diagram shows.

I cut the two wires as directed on this site. Tested each end with the meter while holding down the lock/unlock button.

Plugged in the hot wire last, instantly started to melt. Unplugged it.

Hooked back up one of the power door lock wires. Started to hook up the other one, it starts triggering the lock when it's connected and won't stop.

Passenger side works on the lock feature. Driver side button feels stuck. It won't move. What the heck happened to it?

How in the world could this setup have failed like it did the second time?

I cut the two wires as directed on this site. Tested each end with the meter while holding down the lock/unlock button

what color wires are you using from the cars? are they tested before using? if so how?

-------------

It was the Pink / YELLOW and Pink/Light Green .

https://www.the12volt.com/installbay/alarmdetail/890.html

Now that I think about it.... I was only planning on wiring up the driver door so I didn't needlessly wear out the passenger door lock actuator. The P side was still hooked up and untouched.

Could that have been what caused the problem?

Are you saying that you cut the pink / YELLOW and pink/lt. green and connected the wires from your relays to the side facing the driver's door?

Or that you connected the wires from the relays directly to the pink / YELLOW and pink/lt. green without cutting them?

The first case would probably cause a short circuit, since most older reversing polarity doorlock systems are grounded through the driver's side switch. The second case definitely would be a short circuit.

It's really not worthwhile to worry about avoiding the passenger actuator(they are dirt cheap to replace, and it'll be a nuisance the first time you want to get in from that side).

-------------
C Renner's Auto Electronix
My service is cheap, quick, and good - pick any two

i have to say buddy take the car to somebody who knows what there doing

number two why are you burning up wires

you should be using fuses

chriswallace187, I connected the two cut wires to the relays just like in the diagram I linked too.

How did it cause a short and how would one get around that happening?

That diagram is correct. You are missing something somehow.

You still are not fusing your power wire for the relays - big, big mistake. If you are fusing it, what is the rating?

-------------

I just had the relays connected straight to the "yellow wire" in the column assuming it was fused.

I was using 16 gauge wire, so I image the ~10 gauge power/ground was able to carry that much current; hence the resistance in the 16 gauge wire yielding like it did.

In the door harness, there is a lovely fused power source for the door locks already. It is BLACK/ white.

87 on both relays to 12V, 85 as well.
87A goes to switch side
30 to actuator side.
86 is negative trigger from starter unit

Sounds like you have switch and actuator backwards. This sounds hack, but this is the easiest way to find switch and motor side. It works 100% of the time, and you definately know which is which. Cut one of the lock or unlock wires (in your case, cut, say the pink/green). Take a fuseholder, put a 15A fuse in it. Put one end of it to the +12V for the locks (why? because it is right there with the other two wires..... no sense over complicating things). Now, you have 2 sides of the cur wire, right? Touch the other side of your fused 12V to one of the ends of the cut. Big spark, fuse blows, you just found your switch, as it rests at ground. Doors lock? You just found your actuator side. 87a on one of the relays goes to the switch, 30 on the same relay goes to the actuator side of the cut. Repeat for the other wire (or, now that you figured out one of them, the other wire is wired exactly the same, using the other relay).

5 wire locks aren't that bad at all...... too many techs overthink them, and in the end cause far more work than necessary for themselves.

-------------
Wherever I go, that is where I end up......