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Not sure if any are directly related to each other but they all did seem to happen at nearly the same time.

My gauges and dash backlights dont work. My tail lights also dont light up, the blower doesnt work, and the gen light is always on yet my voltage meter shows its still charging the battery properly.

Ive cleaned all the grounds i could find checked for loose wires and right now its beyond me to what may be the cause.

What year is your truck?

Sounds like the Voltage Regulator.

Also check the fuse box, pull all the leads off the bottom and clean them if there is any sign of corrosion. A little baking soda mixed with water and an old toothbrush do wonders. A small brass bristle brush works well too.

Good luck, let us know what you find.

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"If we did the things we are capable of, we would astound ourselves" - Thomas Edison

Thank your for the reply, its a 79. Right now i have it sitting at the farm 60 miles from here but when i get out there this weekend ill clean up all the connections and see if thats the problem.
Also how would i test the voltage regulator to see if thats the culprit?

Testing the VR is a bit of a pain, but you can adjust the air gap on the coil if you need to. It's usually a lost cause though.

My recommendation is to get a solid state unit at Napa (they run about $25-30), before you head out to the truck. Here's the NAPA PN: MPEVR550SB. Don't install it until you've cleaned up the rest of the stuff though, or you risk damaging it. A little 'gotcha' on these trucks is the plug style for the VR, I think '79 may have been a crossover year and there are two styles of connector. I know the '80 used a round plug, but my '78 has a rectangular plug. The PN listed is for the rectangular plug.
Maybe another '79 owner will chime in here?

Grounds are another thing to check, for the conditions you've mentioned. There is a ground cable from the battery tray to the block, make sure it's there and in good shape. The battery cables are an obvious check. There are also two chassis wiring harness grounds mounted just in front of and above each fenderwell. These often get broken off and are worth checking. Clean 'em up when you do the fuse box. You may need to crimp a large eyelet on where they are supposed to bolt to the fenderwell, they tend to break off and just sort of hang.

Good luck

_________________
"If we did the things we are capable of, we would astound ourselves" - Thomas Edison

check the fuse box mine was doing the same thing and it was the contacts between the fuse and connectors i a tooth wire brush and it seemed to help but if you want to just get it started to get it to your house or what ever play with the fuse with the key on popping them in and out eventually you should hear every thing start to work its sound like jury rigging but it gets you home

I've got a 79 longbed and it has the rectangular style connector for the VR. Also, my truck had the same problem a month ago and it was the connector right off the positive battery post. One of the 2 fusible links was loose and causing electrical issues. Easiest way to fix is with another connector from a parts truck.

Thanks posting about the grounds on the wire harness. I am going to check mine. I added an extra ground cable I put on one of the bolts on the bottoms on the motor, and then other side goes to the frame.

Thank you for the help everyone. Had 1 broken ground and had to clean up the wires on the fuse box then everything came back to life.

Glad to hear it . Which ground was bad?

_________________
"If we did the things we are capable of, we would astound ourselves" - Thomas Edison

Their was one splitting from the engine to the frame and that one was broken. It appears someone had previously twisted the wire together.
I also added a cab ground since i couldnt find any ground going to the cab itself.

I've seen trucks where the engine to frame ground was completely missing. Glad to hear you found your problem.

_________________
"If we did the things we are capable of, we would astound ourselves" - Thomas Edison