I am creating this thread with the hope that it might help somebody encountering the same problem I did.

my car is a 1987 formula.

here are the symptoms I encountered:

1. all gauge/instrument panel lights suddenly stoped working.

2. The “you left your lights on“ chime stoped working.

3. The ( factory) radio display worked until you switched on the headlights or the parking lights (The display would go dark). But the radio continued to work fine.

4. all fuses were fine.

5. The headlights still work fine.

6. apart from the light, the gauges all work fine.

7. The “you left the door open“ interior lights still work fine.

The solution to this very specific problem was replacing the instrument panel dimmer switch (at least that’s what it’s called on rock auto). It’s a little confusing as there are actually two different parts that look similar and are called by similar names.

another counterintuitive aspect of this problem is that it has nothing to do with the actual physical rocker light switch located on the left side of the dash.

Here is what the part looks like. It is located to the right of the steering wheel, underneath the dash, next to the OBD port.

 

Looks like a Firebird?

Around here, people refer to that thing as a "dimmer module". Fairly common for those to go bad.

 

It still took some searching to find an answer, and even then it was not definitive. Just trying to help someone in the future.

 

Yep, remote dimmer, Firebird specific. Camaros have it built in the HL switch.

 

Good to know ResIpsa. Thanks for sharing.