I have an 85 Camaro. When I turn the head lights on the voltage gauge drops to nothing, sometimes the right directional indicator lamp will come on and glow solid without turning my actual directional, and at least one of the backlights for the tach doesn't work.

Does anyone have any idea on what’s going on here?

 

Without a schematic of year model, venture to guess loss of ground (Bat Neg) for the headlight circuit. Think circuit trying to P/U grd thru signal light that glows.

 

MY 83 z28 did the same thing. New headlight switch did not fix it. My instrument cluster was not pressed into the connectors fully. Our gauge clusters are press-fit plugs. I loosed mine, pressed it tight, and then bolted it back up. worked perfect ever since.

 

Gently take out the gau. cluster. Check for signs of corrosion on all contacks. Male and female. Clean with rubbing alchol a q-tip and a reassemble.