68 electrical gremlins...

[HIGHWAY BY THE SEA]

My wife was driving my 68 C10 stepside days ago, and lost ALL power. And I mean all power for EVERYTHING. I was in Georgia, so she had the truck towed home. The lights do not turn on, the horn does not work...NOTHING. Since then I have checked the following:
Ground cable
Positive cable
Battery (11.6 volts)
Power wire (has power from battery to firewall)
Ignition switch (has power and tried another to be sure)
Visually checked the wires around the fuse box, and they all seem normal. The wiring harness has not helped me at all either. Any ideas from the experts?

[gmc684x4]

Hidden but splice in the main power harness ?
Try wiggling the wire see if you get power back
a broken wire can do that too

[Grumpy old man]

Fusible link ?

[HIGHWAY BY THE SEA]

The fusible links all check fine.
Is it possible that the voltage regulator has gone dead? Would this cause power outage?

[dmjlambert]

Is it still broken, or intermittent problem?

[firedemon]

voltage regulator is only a part of the charging system it dosent really supply voltage to anything else . if you have power to the key switch your going to have to start checking from the key to each circuit it supplies . really sucks but I dont see an easy way out

[gmc684x4]

How old is the wiring in the truck ?

I had that happen to me up a mountain side cruising in my 68
it stopped nothing worked I got out started wiggling stuff I could hear my fan once I wiggled the main power wire pulled back the wire loom found a bad connection in a but splice had to find a sharp rock to scrape that wire back enough to hand twist it together to get home
I solder all connections now since that trip

American Autowire makes a great product buy the whole thing or parts as you can afford them places like Brothers trucks sells them

I bought the complete set for my dads 72 chevy heck this truck has 72 xxx miles one it

I dont know about you I would be heart broken to have my 50 year old baby burn down because I got cheap with her wiring harness

[HIGHWAY BY THE SEA]

The wiring under the hood is brand new. Everything else is presumably Factory. But it is in very good condition because I have checked it myself. And I know that there are people in here who believe that fifty-year-old wiring should be replaced and they are probably right. But I am of the mindset that if it's not broken don't fix it (yet).

[rpmerf]

I'd be looking at loose terminals or a bad ground. Get a test light and start poking around. Clip it to the positive and verify good ground on the body. Clip it to positive and follow it. Hit the junction blocks, back of the alternator / generator, various fuses in the fuse block. See if IGN UNFUSED gets power when you turn the key to ON.

[Hutch]

My 71 did this the other day
Somehow I kicked a wire loose from under the dash that was connected to the fuse block
Plugged it back in and everything was ok

[Steeveedee]

Sounds like battery failure to me. 11.6V is dead, anyway. Try swapping in a different battery. These newer batteries have the plates closer to the bottom than in ears past. Once some crud flakes off the plates enough to short out some plates, they're history.

[gmc684x4]

here is wire schematic do you have power at the junction block ?
if so follow power from there back use a meter not a test light then you can read what voltage you actually have

[68Gold/white]

I may have suggested this on your 67...Under the hood, the wire harness plugs into the fuse box by the steering column. Unplug it to make sure all the connections look OK, nothing looking like it got hot or burned. The main power wire is connected with the same type of connector, and it can get hot and melt the plastic the holds it in place.

[HIGHWAY BY THE SEA]

The truck is fixed!! Kudos to all who suggested the ground wire. Today I finally found my missing jumper cables, (and time to work on the truck) and I jumped the negative battery terminal to a ground. This made the lights work, so I removed the negative battery cable and found a crack on the bolt-anchor where it attaches to the alternator bracket that was invisible, AND which always registered a ground when I tested it with the meter. I had checked the wire visually, and with the voltmeter, without removing it, so I will NEVER make this mistake again. Thanks again to all who helped, with a special nod to Maddkidd007, who has gone out of his way to coach me along on this.

[68Gold/white]

Tell your wife, she has nothing to fear now!!!

Can't have too many grounds!!!
Things I have grounded that I have learned from others:
1. Attach a wire to one of the vacuum advance wires, run other end of wire to where neg cable is attached to engine.
2. Do same with alternator case...
3. Make sure engine is grounded to body, with atleast one ground cable, 2 ground cables would be better. Chevrolet ran a braided cable from a valve cover bolt to the fire wall on all engines. They got thrown away after first set of valve cover gaskets were replaced.
4. Ground the body to the frame. The factory ran a small braided cable from a body mount bracket to the body. These are usually over looked on a complete build, or rust away.
5. The steering rag joint has a brass strap in it, to ground the column....

If you have a classic vehicle of any kind that has electrical gremlins, think about these...