Instrument illumination comes on when headlight switch is off and ignition switch is on, and goes off when headlight switch is on.

Anyone seen this before?

Diagnostic suggestions?

 

Dimmer roller perhaps?

 

Yup, mine turns off just past the max-bright setting on the dimimer potentiometer.

 

The pod lights are always on bright - they go on low when the lights are on... the low is variable based on the dimmer - if the dimmer is out (or if there are any other problems with that circuit) the pod lights will simply go out when the lights go on... as in your case.

Alan

 

Thanks.

 

I sprayed some WD40 on my S4's dimmer wheel and rolled it back and forth several times. Some pieces of corrosion fell out and the switch has worked perfectly ever since.

 

I had the same exact problem with my '89. Turned out the PO had used a headlight relay from an earlier car. When I replaced it with the correct part, it worked fine.

 

Eh what....?

I can guarantee the headlight relay has absolutely nothing to do with this issue... (don't go there). The pod lights are related to the marker lights - nothing else.

Alan