Ive searched for this isssue, but haven't found a accurate description.

I took my dash off my 02 MC SS to fix my aftermarket radio, but when I put it back on, and tried to drive my car at night, my dash is really dim. I tried twisting the **** but no luck. The automatic headlights still turn on, and when the **** is pulled, the interior lights come on, just no brightness on the dash. The blinker symbols light up when i use them, but the lighting for the odomter, gas level...etc doesnt light up. Do i need to replace the switch or harness? or could something be unplugged or anything else? Help needed! thanks in advance.