1973 cuda,dash lights are really dark almost black,switch works bur very very dim on dash,bulbs are ok,radio light works could it be the switch,,the voltage regulator? need help. thanks.

My uneducated guess would be the ground for the light bar or corrosion on the tips of the bulbs.

I'm thinking the rheostat in the dimmer switch (too much voltage drop). I'd start by jumping 12V to the "out" terminal in the DS & if they brighten up then work upstream from right there starting with the switch itself.

there isn't a voltage reg for the dash lights.
they do go through a reostat either in the headlight switch or a seperate roller switch(but I think that was only 68 cars). not sure on yours.

it could be the contacts are bad or corroded. Could also be poor ground to the dash frame.

some people just roll the switch around multiple times to try and "grind" off the crud on the spring.

if that doesn't see to change anything, I would add an extra ground to the dash from and see if that helps.

Has anything changed recently or has it always been like that?

Mine were dim in my 1970 cuda. Checked dimmer switch,ground,wiring everything was ok, ended up putting in the LED bulbs and it made a huge differance.

Agreed, access that copper strip on the printed circuit that grounds the bulbs & ground it directly & see if they brighten up

You may want to PM member: crackedback...he sells two/four system wiring kits that greatly brightens headlights, along with dash lights.