Hi,

I am having a problem I can't figure out and could use help on. I have a 1984
F-150 that I can't get the instrument lights to work. The other dash lights seem to work fine, turn signal, seatbelt, brake and high beam indicator all light up. It seems to be the lights that are dimmable through the headlight switch. I checked the switch and everything seems OK other than that, when I pull it the headlights and taillights come on and when I twist it all the way over the cab dome light comes on. I tested all the bulbs and even tested the 5 amp fuse that is for the instrument panel lamps, all are good. I sure would appreciate some advice on how to fix this.

Did you check the copper traces on the back of the cluster?....are they corroded?

If they are, that could be the problem...and if they are, take some fine sandpaper or wire wool and clean them.

The dimmer wiper is also notorious for failure in the light switch. I think most every truck I have I have to wiggle it around sometimes to get the dash lights on. Sometimes they do get bad enough to lose connection altogether. Are the ones in the heat control also out?

Hi and welcome to FTF. Here is a pic of the printed circuit board (from my 1983 F250) and the contacts that Duncan mentioned may need cleaning.

Here's one of the headlamp switch

The wiper on that spring looking part tends to wear out and lose contact, taking all dash lights at once...

Thanks for all the information, I really do appreciate the help! I still can't figure this one out. So far I have replaced the headlamp switch, removed the cluster and cleaned the printed circuit board contacts, and removed and cleaned all the instrument light contacts. Still won't light up. It almost seems that there isn't any power going through the headlamp switch wiper to the cluster lamps. Does anyone know what the pin-out of the headlamp switch is?

I am curious about something, what is the little module screwed to the back of the cluster, just above and a little to the left of the speedometer? I really don't want to take it to the shop since I have already spent this much time trying to figure it out.

I am adding some pics of my truck and cluster.