I've been working on this electrical problem for three days. I didn't have any power to the dash. I read all the threads on that -- checked for burnt fuse links, cleaned up the fuel solenoid contacts, bypassed the clutch switch, put in a new starter relay and ignition switch. Still completely dead. In desperation I once again cranked the motor by jumping the battery to the starter. Cranked but no ignition. I walked away with the key left on RUN. About 3 minutes later I heard my radio. Dash lights were back on and the truck starts now.
I'm glad it's working again, but I don't know what got fixed, and I don't want it to go dead at a bad time...Any ideas?

 

I would start by disconnecting, cleaning, and reconnecting all of the ground wires I could find, starting at the negative battery terminal.

Good luck,
JP.

 

My truck had a similar situation and here's what I found. The PO must have had problems with a fusible link gone bad and didn't know which one so he had a tester and poked through the insulation on each wire to test it (you could see the puncture wounds). Now it seems that one of the holes alllowed the wire inside to corrode and eat through however the wire would still make contact if the two sides were touching but if something moved, like from a rattlin' cummins it would cut out and I'd lose my grid heater. I found this out by getting frustrated and simply turning on the ignition and going under the hood and shaking the whole wiring harness. As soon as I did this I heard the grid heater kick on. You should go over all the links with a fine tooth comb I'd suspect that this is pretty common. I hope this helps.

 

i had a similar situatuation in a plymouth acclaim. nothing would work but the starter. i accidently left the key on after getting done messing with it, and when it cooled down at night and the dew started to appear, all the lights in the car came on and it would start right up. turns out i had a bad ground to the body, and the dew would actually complete the ground enough for the stuff to work

 

Bad connections at the relays on the fenders will do the same on the intercooled models. Just moving stuff around can make the connection come back for a while and the lose it later.

 

I had an old ScoutII that would die sometimes like that, absolutely nothing. Turned out to be a connection at the firewall.

 

Thanks, everyone. I cleaned up the grounds like JP suggested. The big one to the engine block and 3 small ones on the body. It took 10 minutes and power is back. Knock on wood.

I still don't understand how a circuit's shorted and then 3 minutes later it's not???

 

Corrosion is an amazing animal. It puts the beast to sleep when you need it the most and awakens it when least expected. When you mix metals, allow oxygen to come into the picture and supply a DC current, it grows. Slowly, quitely and most assuredly.

 

That sounds like an ad for a horror movie from back in the fifties.