Ok been playing with this issue with Daughters car. 2004 and brake light switch getting HOT and melting wires. On Wed night came home and her car was in the driveway and brake lights were ON and no one in the car. Could not touch the brake switch because it was so hot. Have traced everything and can find not issues with ANY wire all the way to the lights. Now I do see in one or two light socket they are arching for some reason. She has aftermarket housings for the light and note a little water in them from time to time. I have dielectric grease in them but still getting this heat issue. Anyone have anything else I could check?

 

have you bothered the check the switch itself for sticking?

 

My guess, and this is JUST a guess, is that cheap quality aftermarket lights have introduced a voltage leak, causing damage to the brake light switch over time, and now there is an internal full blown short in the switch.

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Well this time put in another new brake switch,, but this time put in an inline fuse so it will now go before anything else gets too hot.