When I purchased the truck it had off road lights on it, I upgraded the lights and put a new set on there. 2 mornings later on my way to work I started smelling something burning, and it was my light switch wires. I disconnected some of the new lights to see if voltage was an issue. But the parking light harness that plugs into the back of the light switch are getting hot and mooshy. Ended up disconnecting all of my lights and it was still getting hot! Any suggestions on how to fix this problem?

 

If the wire is too hot, its not rated for and cant handle the current passing through it. Youll need to replace the wire that is overheating with a thicker gauge. Do the math, if the load (bulb) you added is drawing more current than the wire can handle, itll catch on fire.

 

Also, sounds like theres a short in there as well. Be more specific about which harnesses and which wires.