Just noticed something on my truck, when I have the headlights or running lights on and have to turn up the dash lights for visibility. The control(rheostat?) for the brightness of the lights gets real hot, I'm thinking that either my truck has a ground issue on this switch or maybe it has some different headlights-nonstock? any one run in to this?

 

It's common but usually the other way around, the switch gets hot when the lights are dimmed.
This is because the rheostat is "lighting up" instead of the lamps.

 

if i dim the lights on mine the dash gets extremely hot. i've been considering drilling a hole in the air duct to get some cooling to the switch. anybody tried this yet?

 

yes. Mine still melted again. There is a relay harness to take some of the power off the switch. Plus I switched to LEDs on my flatbed to cut the amount of current flowing thru the switch.
Pulling a trailer will heat the switch up also, because of the extra lights on trailer that are powered thru the Headlight switch. I may have to go to LEDs on the trailer also.

 

Been tried and, by most reports, works well.

02's have less serious problems (melting wires or fires) than earlier yrs...but do still get warm.

RJ

 

The relay harness works well,I made my own. Do a search on this forum and you will find quite a bit of info including where to get the harness.