Hello all! It's been a while since I posted here, hurricane Florence reprioritized many things in my neck of the woods. So I have a dilemma regarding my instrument cluster, the only lights that work are my idiot lights(oil and charge) and my bright lights indicator. That much tells me that it is getting power to at least those three. I know that all of the bulbs are good because I tested them before placing them into the cluster when I got the trunk. Same goes for the blinkers and emergency flashers, I can hear the relay clicking but nothing on the dash(everything works in the rear of the truck, up front only when they feel like it). My fuel and temp gauges work, just no lights. I didn't see any visible cracks or breaks on the circuit film on the back of the cluster when I replaced the bulbs so I am at a loss for where the issue could be. My first thought was a bad ground, but then would any of the lights work? All the fuses are good, and the wiring coming out of the fuse panel is all tight with no loose stragglers. I apologize if this has been covered elsewhere, I searched for anything I could find on the instrument clusters and did not find anything pertaining to these specific issues.
Any suggestions or insights would be greatly appreciated.

 

Year? Make? Model?

 

I went through about the same thing. Getting the outside blinkers to work - I hosed the turn signal switch out with tuner cleaner. Getting ALL the bulbs to light was a meticulous cleaning job on the bulbs, sockets, and the plug connector and the printed circuit where the connections are supposed to be made. One trick I learned is the bulb tests good by itself, but they were NOT making contact properly in the socket and I had to tweak them a bit to test good - IN THE SOCKET. Then the sockets have to test good plugged into the printed circuit. I chased issues on and off for about 4 weeks before I got ALL of mine working. Good Luck !!!

 

Oh wow, I'm a putz. I thought the make and model were in the post. It is a 1984 F150 base model.

 

The following link is for a 85, I think yours should be the same. Double check if you have a diagram for your fuse box. Look on page 13 in this link.

Fuse Panel & Circuit Protection - Gary's Garagemahal (the Bullnose bible)

I know you said the fuses are good, but now we need to check for power. Get a voltmeter or testlight, put the black lead on a good ground. Turn the headlights on, and then take the red lead or the probe on the testlight, and poke the instrument lighting fuse #17. With the headlights on, you should have voltage on both sides of the fuse. If you do not, while holding the tester on the fuse, turn the headlight **** back and forth and see if you get anything. Write back in with your results. Depending on what you get, we can point you in the right direction to look for the problem.

 

The warning lights each get their power from different places than the dash lights.
Same goes for the turn lights in the dash. (man I forgot to check mine )
Gauges also get power from a different place than all of them.

Now when I said I did not test my turn lights in the cluster this was after I did LED bulb swap.
I did have to "play" with a few of them to get them to work and this was after I used a pencil eraser to clean everything.
Dave ----

 

And when you get done your will feel like an "Expert" on your dash wiring, and know it like the back of your hand... LOL

 

Yep and that was the 2nd time I had it out and apart.
I pulled the one from the project truck and the parts truck to use the best parts to make 1 good one.
When apart I cleaned all connections, painted the needles and a member sent me a tech with the circuit film to swap in.
Only thing I did not do was replace the dash bulbs. When I tested all worked but the dash bulbs so out it came for the LED's.
When I got it back in I tested everything but the turn bulbs & brake light warning. Next time I get out I will test them.

Oh I also swapped out the trucks wiring harness between the 2 trucks because of duel fuel tanks and AC so I know my truck really really well
Dave ----

 

This true...sometimes all you need is a bumpy road to get the lights to work!
BB2

 

Thank you all for the replies! I had a few minutes today so I hit the fuse box with the test light. I have power to the bottom terminal of fuse 17, but not the top, this is regardless of how far I rotated the dimmer switch with the lights on. The ground I used was the mounting bracket for the steering column as it was the cleanest I could find with my limited amount of time.

"This true...sometimes all you need is a bumpy road to get the lights to work!"
BB2

So true, I hit a pothole the other night and my left turn signal light started working, then stopped a day later lol

 

You will not have power on both sides unless the fuse is in place. Sounds like the headlight switch is passing power to this fuse. If you want to make sure, you can put the fuse in place, and test for voltage again. The fuses have a little spot on them where you can put a sharp probe.

Good voltage on the fuse and no lights means you have a wiring problem. Any wire you find that is lightblue with a red stripe is the wire you are looking for, this feeds all the dash lights and the cluster. This wire goes around all the dash to all the illumination bulbs, even the ones in the radio.

 

So I pulled the fuse box today and sure enough, one of the blue wires with the red stripe was cut. I wired it back up and now I have power across the fuse, but still no lights. Hopefully, over the weekend I will be able to pull the dash and dig into the cluster itself. Plan of action will be to test the blue/red on the harness feeding the cluster for power, if not try to find the break. Then on to the ground for the cluster that the EVTM says is G701 near the radio. Then if both are good on to each bulb connection/socket. If I'm missing something, or there are any tips or tricks that y'all know of it would be greatly appreciated. Thanks again for pointing me in the right direction, this forum is awesome!

 

You are on it. Just remember lightblue/red stripe. You should have one of these going into the large plug that feeds the circuit board on the cluster. You can test for voltage on that wire. That is the point that feeds all the cluster lights. You should have a couple of other places that the lightblue/red feeds, like the radio and the illumination for the heater controls. I can't remember if these trucks have illumination for the headlight switch and wiper switch?.