Happy new year everyone. I've got a 76 F-150 4x4 w/ a 360. About a week ago I changed out the back plate to my instrument cluster, cleaned up the circuit board, and put in some new light bulbs so I finally got my gage lights working. Drove the truck once since then and noticed my temp gauge wasn't working, which it did beforehand. Now taking it out today to test a new AFR gauge, and come to find out my turn signals in-cab don't work and my gas gauge was swing around from 1/2 to full. Can anyone point me in the right direction of what's going on here?

 

With several things being an issue at once I would be leaning to your ground Possibly bad connection at connector behind cluster. Maybe pealed copper strip or folded on you. Also check the metal pins on that connector. Might just be pushed back out of position. I have 1977 and number 9 on the connector is my ground for instrument cluster.

 

Test the temp gauge to verify it is in working order, & was not damaged when removed & reinstalled. To test, connect wires to the two studs on the back of the gauge. Connect the other ends of the wires to a 1.5 volt battery. Wait 20 seconds or so, the needle on the gauge should go up about 1/4 scale. If it doesn't reverse polarity, try again. If the needle doesn't move, gauge was probably damaged when removed or installed. It is very easy for the stud to spin & break the very fine wire inside. It is possible to disassemble the gauge & reattach the wire if you are patient. You can test the gas gauge the same way. Use 2 batteries for 3 volts, gauge should go up about 3/4 scale.

Pull the bulbs & sockets for the turn signals & verify they are working. I use a battery charger with wires attached to alligator clips. Clip on to the contacts on the bulb holders, see if the bulb lights. If not, you may have to clean the contacts in the bulb holder, bend them out so they make better contact, clean contacts on the bulb, replace the bulb, clean & bend out the contacts on the bulb holder where it contacts the PC. I test everything before I install it on a cluster I am rehabbing. I test each bulb before it goes in the holder, then the bulb when it is in the holder. Next I install the holder, & power the bulbs thru an old plug inserted into the PC. There's a few different places for faults to occur, you have to test each step of the way.

 

Thats some serious testing. Can't say it won't work though. I really appreciate the help guys. Should be working on it tmrw so I'll let ya know what the issue was

 

The turn & gauge lights use the same ground path on the cluster. So, if your dash lights work, the ground for the turn lights is good.

 

So as it turns out it makes a big difference when the connecter in the back of the gauge board isnt fully connected. I don't think it's fixed the temp gauge but all the others working is a good step