I now have a 2001 Cavalier Base Coupe 5spd (Yay) and I knew before buying it that the gauge backlights did not work. I have a feeling it is the dimmer switch probably unplugged, because the previous owner stated they replaced the original 3 gauge instrument cluster with a 4 gauge. What I noticed when I picked up the car, is the Anti-Theft light is constantly on EXCEPT when the headlights are on. Even with the key off, Anti Theft light stays on.

I am curious if anybody has an idea what's going on there, because the wire diagrams I currently have don't show how the Anti Theft light and the Exterior Lights are connected.

 

Mix and match parts and you end up with a Frankencar. Find the proper instrument cluster for your car and those annoyances will probably disappear.

 

I have tried re-installing the original cluster and seen the issue still persists. Same Anti-Theft System light, no panel lights.

I will confirm my original assumption, the dimmer was indeed unplugged. However, plugging it in did not help; in fact the Odometer now goes completely off when the lights are on.

 

have the codes read. the cluster is the theft module irrc

 

Cars, like people, gain personality with age. Few things are more boring than a perfect car, or a perfect person.