98 C2S coupe MT
Instrument lights come on with parking lights but go off when headlights are on, I'm guessing it must be light switch????

Any advice appreciated, TIA, Jack

 

That sounds about right, the switch is suspect if you speak of the backlights. Replacing the switch is not hard. It is removed from the lock mechanism and unplugs from the wiring harness.

 

Correct behavior.

 

Are you talking about the backlighting for the gauges or the green indicator in the clock? If green indicator, normal. Backlighting behavior like that is abnormal.

 

All of the instrument lights

 

Gotcha. Not normal at all. Do the headlights work correctly? If so, start with fuses and relays. There is another recent post on this that may help.

 

What puzzles me is the instrument lights all work with parking lights which leads me to believe it must be the light switch.

 

Jack- The instrument light circuit is driven by terminal 58 on the switch. In a healthy switch, terminal 58 is energized in both the "parking light" and "headlight" positions - everything else about the circuit is the same, so the problem has to be inside the switch. Terminal 58 also drives the license plate lights, so those will also go out in "headlight" position.

 

Thanks Jay I will check it out next week when winter is over :-)

 

oh sorry I thought OP meant the green indicator light