Headlights On, Dash Lights Out!

[Kimbrough]

New problem on a 1991 Grand Wag. When I turn headlights on, the dash lights go out. The clock stays on but is dimmed as it should be. I checked the dimmer switch to no avail. Any help is appreciated. Fuses look fine btw...

[Stuka]

I would check grounds first. All of the weird issues I have had with lights have been related to grounding issues. Lights flickering and such. I have had issues where the scrubber inside the dimmer gets some corrosion on it, and I have to turn it back and forth a bunch to get it to work again.

[Rinkle_Stinkle]

mine was a wiring issue (melted wires). I've heard the rocker switch for your headlights can cause this since it was their ingenious idea to run all running lights through that one switch. you can get one super cheap and its not extremely difficult to replace. id try that if you don't find a lose wire or a short.

[Kimbrough]

M'k so why does my dimmer switch have oil on it?

[FSJ Guy]

Because you have a mechanical oil pressure gauge that is leaking???
<shrug>

Ground faults will do strange things. X2 on checking grounds.

[81waggy]

Same issue on my 81. 3 fuses were blown and a bad ground from my new radio install. Didnt make sense why but replaced and relocated, everything worked fine after

[Kimbrough]

I FINALLY FIGURED IT OUT! OY!!! IT WAS THE 3AMP FUSE FOR ACC AT THE BOTTOM OF THE FUSE PANEL. ALWAYS CHECK FUSES FIRST!!!