I am sure that the answer is gonna be simple but after rebuilding the cluster on my 57 BelAir the light are way to dim. I tried adjusting them brighter withthe switch but it didn't help. I made sure to ground everything correctly and even took it out again and changed the blubs. The lights are barely enough to make out the numbers but can't seen the needles at night. Next I had the standard bulbs replaced with LED bulbs and it the same. I will say i think the LEDs are pointing the light straight forward where the standard bulbs seem to spread the light to the side more. Anyway.... with out embarrassing to bad, any suggestions?
The rheostat on the headlight switch could be corroded or partially damaged and causing not the full voltage to go to the lights
Cheap China leds 25 where Like $7 Free ship , 6 or so years old I have them in 4 different vehicles Usually LEDs only work one way , (Light Up) Correct wire for Ground , & positive. Head light switch Good on interior/gauge lights. , On full Volts ? Not turned down to dim /off ? ,
Take a bulb and test it on the battery you are using. Is it bright? If so you are not getting 12 volts to the bulbs in the dash. Next run a wire from the power lead that goes to the headlight switch, directly to the dash light harness. If the bulbs are bright now you have a bad switch. If still dim, you are not getting full 12 volt power to the switch, or the ground to the dash is questionable.