no dash, radio, gear shift lights
 

i have an 88 420 sel. I have replaced the rheostat (dimmer switch) and
have even hard wired it. Still no dash or other common lights
controlled by the rheostat. Have also replaced fuses. Have all other
lights including glove compartment and visor lights ok.
Any other suggestions on this problem. The rheostat controls lights for
console, radio. I have none of those either. Also changed bulbs in dash.
They still will not light up.
Thanks:confused:

Seems unlikely, but start checking bulbs. If not that I'd just have to guess a cracked solder joint that feeds power to the dimmer.
Gilly

Same problem on a W123
 

I'm troubleshooting same problem on a W123. What do you mean when you say you hardwired it? Did you hardwired bypassing the rheostat? Did you ever find your problem?

Is it possibly a broken or loose ground wire?

Check continuity on one of the wires in question to a different ground location. I believe the grounds for the dash lights are on a bolt bhind the dash itself or perhaps below it.