Hello, I just purchased my 76 f250 highboy about 2 months ago and having a hard time figuring out the instrument cluster lights. I installed all new bulbs and still cant get them to work, The lights above the wiper and headlight ***** work and the lights for the heater control works. The dimmer switch works as well. But I have no lights in the cluster its self. Turn signals work on the out side but do not flash in the cluster, nor does the high beam indicator. Anyone one had the same problem or suggestions?

 

Pretty common. remove the cluster and clean the bulb sockets and all contact points real good. clean by actually scraping the copper not just wiping it with a cleaner.

 

Seems odd that not one of the lamps work on the instrument cluster. I would check the multipin connector going into the cluster and specifically check for power on the blue with red stripe wire when the headlamp switch is on, of course.
There is also a black ground wire coming out of connector that must be grounded so make sure it is. You can find a wiring diagram by scrolling through the "Ford truck information and then some" pinned thread at top.
An old fashioned pencil eraser works good for cleaning those copper printed circuit contact points as 440 sixpack mentioned . This is always a good idea for preventive maintenance no matter what.

 

I have to just ask, you have rotated the headlight **** switch in both directions and tried to dim and brighten the lights? If I remember right (full clockwise is dim/off) and full counter clock and before the click (to turn on the dome light) is full bright. I 'd say yes that part is working if you can see the headlight/wiper switch legend and environmental control panel back lights brighten and dim when you turn the ****. But it is the 1st step IMO on troubleshooting.

Ford truck information and then some link https://www.ford-trucks.com/forums/1...then-some.html

Elec diagrams/info start on post #8

 

I did the pencil eraser thing on the circuit board. I also turned the light switch to left and right with no luck. I will check the ground wire and voltage in the blue/red wire and let ya all know how it turns out.

 

Check each & every bulb for operation with it out of the holder. I use a battery charger, hook the leads to the bulb.If the work, good. If not, clean the contacts on the bulb & re test. Or replace them all with new, but test new ones too, especially chinese bulbs.

Then clean the contacts on the bulb holder, both inside & out. I use a cut down fingernail file to clean the contacts inside the holder. Bend the contacts inside the holder in, so they are tighter on the bulb. Bend the contacts that touch the PC so they make better contact. Install a bulb, test thru the holder with the battery charger.. Be prepared to fiddle around with each one to get them to work.

With the cluster removed, install the bulb holders. Trace the PC, figure out what trace powers each bulb thru the plug socket. Then use your battery charger to power each circuit, Verify each bulb lights. Be prepared to fiddle with them to get them all working. Once they all test good, install the cluster & you should be good. However, if the body of the cluster is crumbling, it is just about impossible to get lights to work.

You may have to clean the contacts on the PC in the plug socket as well. Clean the harness end of the plug too.

I have an old harness end of the plug that I pop into the cluster with all the wires marked, this makes it a lot easier to test clusters.

The key is testing everything as you go, every step of the way. Don't trust anything without testing it! There are no shortcuts to this process, start at the bulbs themselves.

 

Thanks everyone!

I found scraping the contact points with my pocket knife did the trick. Pencil eraser wasn't quite enough. I just found it odd that not a single one of them would work. They are all working now!