2001 Cadillac Catera dash light went off not working

I would suspect that you blown a fuse, which fuse box did you check. If you talking box, and it was under the hood, it was probably the wrong one. The correct fuse panel, would be under the drivers side bolster, below the steering column.

In this particular case, is it just the instrument panel backlighting that is inoperative? What about the headlight switch, the drivers heated seat switch, hazard switch, and fuel door release switch. In fact, looking at the schematic, all switches are on the same circuit, anything that uses dimming. I would find it highly unlikely that all bulbs in the cluster went out, but if everything else on the circuit works, then you will need to dig into the cluster a bit and find out.

I would guess then that you have no power on the circuit. It is clamp 58 fuse #26 that I am showing. Power from there goes to the headlamp switch pin 1, a gray/green wire. From there it exits on pin 2, a gray/yellow wire, and goes to a splice where it splits everywhere. If fuse #26 is good, check also that there is power to and across it.

Did you determine that that fuse is definately good, and it has power across it. If it doesn't that could suggest a power distribution issue further up the line. If it has power across it, then next would be to check power to and through the headlamp switch, and if it is on pin 2 out of the switch, then it would be circuit diagnosis. Which may or may not be within your capability. Tell me if that fuse has power across it, you can probe both sides of the fuse with a test light to ground. If the light lights on both sides, you have power on the circuit. One of the circuits from that splice goes to the radio for dimming, so you could have easily shorted it.