dash light problem

[KWinBigE]

First, I just bought a 71 Custom 10 and I sure appreciate what a wealth of knowledge there is on this board. Already picked up a lot of good info.

But.....

Here's one I haven't seen before.
The dash lights on my '71 work but are real dim. I turn the knob all the way just short of the dome light coming on and they get a little brighter but still very dim. All external lights and signals work as advertised.

Here's some possible clues.
Both turn indicators come on (and stay on) when I turn on the lights, but the signals and flashers still work fine.
The dash lights are even dimmer when the high beams are on.
The dash was replaced with a tach dash (before I got the truck).

I'm thinking it might be a printed circuit board problem?

Any suggestions for troubleshooting further will be appreciated.


Thanks,

Kim