I have a 1987 Silverado, HD 3/4 ton that my son drives. It's a project truck that is in pretty good shape with a crate 350 that has 9,500 miles on it. We've cleaned it up and have done some work to it.

Last week, the instrument panel lights went out. Replaced the bulb but it didn't fix the problem. The lights for the radio and temp controls still work. The weird thing - if we turn the light switch to turn on the dome light the fuel, temp and oil pressure gauges drop. It we turn it clockwise the gauges begin to work properly. Was thinking there was a short or ground issue until we discovered the issue with the switch.

Any suggestions? I thought maybe it was the switch until I noticed the radio and temp control lights work properly (they dim when switch is turned clockwise)

Thanks a lot! Also I am new to the forum. We also have a 2005 Z71 standard cab (wife's truck) and 2007 new body 2500HD 4WD Crew with Duramax/Ally (Love this truck!!)