My '76 has lights on the wipers, radio and all that. but nothing in the cluster. all the gauges work perfect..

Any ideas ? the guy I bought it from thinks it's the circuit board. sound logical ?

 

The circuit boards have a habit of disintegrating, so that is certainly suspect. You might want to replace it on principle. Pulling the cluster is pretty easy, so you can check out the contacts between the bulb sockets and the board with minimal hassle. You should test all the bulbs and replace any that have died. The cluster lights are controlled by the headlight switch, so something could also be messed up there. The radio lamp has a different tap on the headlight switch than the cluster lights do, it's not affected by the dimmer rheostat. Try rotating the switch clockwise and back, and see if that does anything. You can also trace the wire from the switch to the cluster and check the continuity. It should be blue with a red stripe. You can find the wiring diagram here.

Good luck!

 

1976/79 F100/350, 1976/91 Econoline, 1978/79 Bronco: TWO different instrument cluster backs, with or without oil and amp gauges.

 

You might also want to check the sockets that hold the dash light bulbs. There are two little copper ‘ears’ that get pressed onto the circuit board when the socket is installed that can become bent back and may not make a good connection.

It was that way for one of the bulb holders on mine, when I was dealing with the same problem.
I also used a pencil eraser to very lightly rub / polish the copper traces on the circuit board where the light bulb sockets connect.

 

I'll check to see if it's getting power but it sounds like if I have to pull it a new curcuit board isn't a bad idea.

 

Following. The instrument lights on my '79 f150 don't work either. Turn signal indicators do, as does the high beam indicator. But no back lighting for the gauges, it's really irritating at night. Turing the dimmer on the headlight switch doesn't make a difference.

Jess

 

I got these twist lock and leds for my cluster. They don't seem to dim but this is the correct twist lock. I had a couple that weren't making contact. So you might try that first.