Thread: Ok WTF!!

So I was out in the garage installing my switch for some things. I decided to mount the switch next to the heated leather seat switch. So I pull the little trim piece off that the heated seat switch is mounted on. And low and behold I find out why my heated seats don't/haven't worked. They were unplugged. So I plug them in and it works, but as I was plugging the in I noticed that they wires running to the switch were all melted looking and kinda crumbling. I just wanted some input from guys who might have felt with this problem. Oh an I did check the fuse. I did that last year when I got the car and they didn't work. It is the right fuse..
Here I'd a pic. Sorry for the quality I took it with my phone.

i would hit up a junk yard and clip that plug off, and solder it in place of that melted one. or find a new pig tail for that plug.

you may even be able to push the pins/ends of the wires out of the plug, and re do the wires with the same metal clips that are on the ends.

Stock chewing on your fingers lol.

Lol I don't chew my fingers it happens at work... The plug itself looks ok. It is the wires just before the plug that worry me.

You know that plug is melted for a reason. It's probably drawing to much current because of a short some somewhere in the resistance grid. Find out how much it's supposed to draw and put a current clamp on it. Make sure someone hadn't put a higher rated fuse in.

It might be a short in the pigtail but if it's in the grid then it might catch on fire.

If it's drawing more current than what it is rated for, replace it or leave it unplugged.

I just talked to lady I got it from. She said it was something to do with a ground issue that happened when they did a motorswap. But I did notice they had wrong fuse in about half of the spots. So I will roll with it and see if anything happens. If nothing happens I will assume they had they the wrong fuse in it.

Replace pigtail or tape the melted wires
Put the correct fuse in the block
Try heater
If fuse blows don't use the heater or replace it

Well I made sure that now the right fuse is in there.... Actually I did that months ago when I realized it wasn't working. But anyway I hooked it up and it turned on and heated the seat with no smoking issue. But the people I got the car from said it didn't start smoking on them till it was on for over an hour.

Ok so I left for work this morning and used the heated seat, and sure enough after about 5-10 mins I started smelling burning wires. I shut it off and the smell went away. But the strange part is that the DIC got REALLY dim about the same time I started smelling wires burning... Any thoughts on where to start?

You are having a grounding or other issue. First off.. your wires look horrible and might be causing the problem. So ...let's fix the visible issue first. There isn't any real power that goes through the switch, I'd take a look and maybe pull the console out to make sure the wires aren't pinched under it.

here's a schematic of how they work


Literally it's power to turn the relay under the seat on and dash illumination.

Thanks for the diagram bill. I was talking to a guy at work who said that the switch or plug might be going bad since that is the only real spot where it is melting at. He also suggested that maybe I have a bad fuse in it that is allowing too much current in the event of a short. Is there any truth to what he is saying?

Also do you happen to know where the ground would be for this so I can check it's condition?

On "High", the temperature is controlled by a thermistor within the grid (element) inside the seat cushion. Once the theremistor reaches a certain temperature it goes open until it cools down. After cool down it closes and completes the circuit until it heats up again. This process repeats itself.

I've seen theremistors fail in the "closed" mode meaning that no matter how hot it gets it never "opens". Semiconductors are like that sometimes.

I don't know what is in the control module but on "Low" it probably controls the temperatue by pulsing the ground circuit.

I can't see how a ground issue would cause what you're seeing. If it were a ground issue then it wouldn't heat up enough.

Can you smell the wires burning when the switch in on "Low"?

I haven't tried it on low yet. I wad actually going to ask is I should try it on low. Also the lady I got the car from said that this problem started when she had someone replace the motor. They told her it was a ground problem. I was just curious as to what wires would have been messed with during a motor swap that would cause this. If any.

Originally Posted by Rico

On "High", the temperature is controlled by a thermistor within the grid (element) inside the seat cushion. Once the theremistor reaches a certain temperature it goes open until it cools down. After cool down it closes and completes the circuit until it heats up again. This process repeats itself.

I've seen theremistors fail in the "closed" mode meaning that no matter how hot it gets it never "opens". Semiconductors are like that sometimes.

It did seem to me like it was getting rather hit. I was wondering if it should be on like a timer or something. So that makes sense. If it is stuck closed I assume that the resistance in the line would just keep increasing. Would that maybe be what is causing the wires to burn?

If the thermistor never opens it will just continue to heat up. This would explain why the fuse is not blowing. You may want to check the control module for heat damage as well.

If it were mine I'd replace the element in the seat or the thermistor in the element. Although the element may not be serviceable and may require complete replacement.

If it works on the "Low" setting then it's probably the theremistor.

Ok so if it works on low I just need to replace the whole dam seat.....LOL... But if it works on low I think i can deal with it for a little while...

Now you're on the right track.

Right on man thanks for your help..... But on a side note I do need to look for a ground issue... I know I do have one.... LOL... When my key is in the run spot and the car not started the Tach bounces a little.. But that is for another thread...

Ground is the black wire on pin E of the switch. What they guy told you is possible. Consider that the switch may be bad and pulling more power than it should. If that happens the fuse should blow. If the fuse is too high of a rating..it may allow too much through.

All the power and module are under the seat. I don't believe they have anything to do with the power to the switch. Power to the switch is low power. The only purpose of power and ground to the switch are for it to tell the module to turn on. Something at the switch is drawing more power than it should or ...wires are pinched/restricted.