Hello everyone, I am new and in need of a bit of assistance. I am a new-ish 2002 suburban owner, but not new to owning gm products. In fact that is about all I care to own, but brand loyalty aside I have an issue that is stumping me. I bought the vehicle about three months ago and have been working out bugs since then. One that I can't figure out is as follows. When I bought the car, it had no dash lights. The lights came on but no dash unless you cranked the wheel until all the interior lights came on and then the dash lit up. The previous owner said he needed to change the headlight switch. No biggy so I changed it. That fixed the problem, dash lights work and will dim. Fast forward a month , and I am driving it across country for my new job. Get into some night driving and I notice the smoke coming out from under the dash. I pull over and shut her down. I also notice the switch is hot as heck. I let it cool down and dim the dash lights all the way out. It stays cool and works just fine except no dash. This past weekend I change the switch again figuring I fried a resistor. After I changed it again I took the old one apart. The thing is pristine. Not burnt so the smoke has to be coming from under the dash. My question is what could be causing it and where should I pull apart to look? The lights still come on and dim, but if I leave them on the switch gets hot and it will start smelling acrid so the dash lights just stay out. This also probably won't be my only electrical as I do have a few gremlins that I am working out of the thing. Thanks in advance.

 

I have had to replace 3 switch in mine...they were all bad so it is possible you got another bad switch.
Another issue could be your headlights or dashboard lights ....if they have been replaced with the wrong wattage it can overload the system. I'd look a bit further than just your lights in the dash as all light powering current comes in and out of that switch

 

I know that the headlights are the correct part number as I have verified them. What is funny is that if you disassemble the headlight switch there are no resistors or current limiting components in there. In fact the wheel is not even a potentiometer. The wheel is a slider much like the in tank fuel gauge sending module (if anyone has changed one of them). The current limiting is done somewhere else. With that said, where do the wires go that come off of that switch, and what route do they take to get there? Does anyone know, short of a complete dash disassembly, if the knee panel, or the dash surround or what. Just wondering if anyone else has had this? And what they did to track theirs down. Thanks

 

So I did some testing today and found out that the heat is being directly generated in the switch itself. If I take it out of the the dash the switch takes longer to heat up, and when in heats up very quickly. Does anyone have a pinout for that switch with voltages or could tell me where to find one? I want to make sure that I am not somehow getting to much voltage in there. Unfortunately it would be almost impossible to check the draw but voltage is a start. Has anyone had their switch get hot? Have you found that these need a break in to heat up and then they work more efficiently?

 

Even tho it's a slider, it can still be a pot. I suspect something that the switch controls is drawing too much current causing the pot to overheat. Could even be some failed insulation somewhere allowing a partial short.