I've had dim dash lights, in a SS dash, as long as I've had the car. Decided to switch out the original pcb to see if it made a difference. I also replaced all bulbs with new ones. Cleaned & assured bulb holders had proper tension & was making good contact. Also checked all grounds. No illumination improvement was noted.A check at the headlight switch showed 12.66 volts entering the switch & 9.44 volts exiting the switch going to the fuse panel & 9.44 volts at the pcb connector. I disconnect the connector at the headlight switch and jumped the power connection & the connector to the fuse block, then measured voltage at the fuse block. It was 12.66 volts & at the pcb connector. My question is there suspose to be that much of a voltage drop through the headlight switch.

Yeah...if the knob is turned to dim the dash lights.

Spin the dimmer the other way to brighten.



If it IS turned all the way to brighten the lights...you've got a defective or dirty switch. You can pull it apart if you're clever and try to clean it; or you can get a brand-new one (probably sourced from India or China) and see if that helps. I'd rather have a repaired switch than a new import--IF it's repairable.

For that matter, you can spin the knob for five minutes and see if the contacts clean themselves. Not especially likely; but clearly the easy solution.