sparky57

Recently purchased a 97 993. While driving at night my dash lights turned off. I switched the headlight switch off and then back on. Dash lights turned back on for about a minute then they turned off again. Repeated the off/on cycling of the headlight switch. Same thing. Dash lights turned on for about a minute. Now they won't turn on at all. Headlights and taillights turn on with the headlight switch, just no dash lights. Prior owner says he experienced the same issue and tried changing the dimmer switch, headlight switch and finally replaced a relay. He can't remember which relay he replaced. He said the relay replacement fixed the issue. Anyone know which specific relay is related to the dash lights? Does the intermittent failure description, prior to complete failure, sound like a failing relay?

Paul M

See this thread, maybe try a search on R24 and R11 for more results.

https://rennlist.com/forums/993-foru...-working.html?

Chuck W.

In 2011 I had the same issue with my '97 993tt. After a lot of troubleshooting, I found that relay 24 was the culprit.

Here is a link to a thread I started on it......

https://rennlist.com/forums/993-foru...ut-solved.html

sparky57

So I replaced the R24 relay and still having the same problem. I did discover though that the dash lights will remain on for hours with only the parking lights on. But when I switch the headlights on the dash lights stay on for a few minutes and then they go out. My car has the Litronic headlights option. I wonder if the headlights are drawing too much current through the relay and cause it to get to hot? Maybe the relay is shutting off to protect itself? Anyone else experience this problem with their Litronic headlights?

ToreB

This has nothing to do with the headlights, this is a completely different circuit.
You could extract the R24 illumination control unit (relay) and jump terminal 58 and 58d on the relay socket in order to test. If the dashboard lights then works, you probably have a defective control unit. It could also be a defective potentiometer (the illumination adjustment ****)
If there's no light when jumped, you probably have a problem with the light switch.
Cheers,
Tore

sparky57

Thanks Tore. I've already jumped terminals 58 and 58d and the dashboard lights lit up. This is the second R24 control unit I've tried and am getting the same failure mode. The illumination adjustment **** (aka dimmer switch) and the headlight switch are also newly replaced. It's interesting though that the dash lights only go out when the headlights are on for several minutes. When only the parking lights are on, the dash lights remain on.

sutherbys

HI, I have a friend with a 1996 993 with the same problem, the dash lights will work with the park lamps on but not with the headlights on.
I never saw your post on what actually fixed the problem ?