Help!...Cab Electrical Problems from HELL!!!

[dyno]

Correction: I edited the post. Courtesy lights (dome light) are fine. It's the cluster lights (instrument illumination) that are part of the problem.

Originally Posted by 1971gmcshortbed

I would bet money you are missing a ground somewhere.

Question: Does the wiper switch need to be grounded by the screws that hold it to the dash? Wipers will only work if it's screwed onto the dash. The wiper illumination lamp stays on all the time when ignition is on - even when instrument illumination is off.