dash lights not working

Another excellent point, the radio is lit by the same orange wire but I haven't actually measured with a meter.
Thanks
Ron

The radio has about 11.60V and so does the two orange wires (one at each circuit board).
That was with car off parking lights on.

So I pulled everything out yesterday and cleaned all board connections and used dialectical grease where applicable.
Found the pin on the driver side board loose and soldered it.
Made up a grounding harness to go to the board and headlight switch and then to the dash stud that the column bolts to.
Replaced all bulbs with 194's and tested each in the new sockets and mounted into the board.
Did a temp. hook-up and still have dash lights about half of the radio light.

The only thing I could think of next was to order LED bulbs so I will have to wait for them to arrive.

Although all of my gauges work properly when driving you can always hear a click from instruments from time to time.
I assume that is the instrument regulator in the gas gauge.
Should I replace that with a new electronic type even though the gauges work properly.
Does that come into play at all with dash bulb brightness?
Thanks again
Ron