mattsvtsnake

I have a 90 Gt that the dash lights are inop at times. When they don't work my tach also doesn't work. Both green turn signal lights stay on in the dash as well as the highbeam indicator. Also the temp gauge pegs out at the top of its range. I turn the headlights off and the tach and temp gauge work as normal again. Would it be the dimmer switch or a bad ground somewhere? Possibly a headlight switch? When I disconnect the dimmer switch the tach jumps when the turn signals flash. Any thoughts?? Sorry for the long post.

Boss_Hotrod

Not 100% sure but you might have a voltage regulator in the cluster going bad. Ive never had it happen to me but ive heard it will cause some crazy issues.