RustyTruck

Heyo, I've been doing as much as I can for a 1978 f150 6.6L standard cab short bed 4×4. I redid almost all the braking system. Replaced oil seals in the transfer case, transmission, and engine, replaced most of the bushings, tires, and shocks. I also got a new starter, solenoid, all the wiring, a few batteries, and 3 alternators. None of them charge. The truck was in bad shape when I got it and is just now almost a reliable vehicle.
My guess is, when the alternator blew, it blew the fuse to the charging system(that's the only possibility I can think of that I haven't done.). I was wondering if anyone knows exactly what fuses my truck takes. Most of them are missing and i got to replace them. Or any other ideas? Battery just isn't charging.

Matthew Burr

well first thing to do would be a lighted check, disconnect all the wires from the positive side (including any on the solenoid) and start checking for a draw with the vehicle off and key out. then follow the wires if theres a draw. some common things that can go bad and cause the battery to short out are the old AM filters (looks like a small cylinder about the size of a pinky finger) or the horn relay (an unmarked box attached to the fender with 3 wires)

Johnboy429bbf

sounds like a bad voltage regulator. 2 1/2 x 2 1/2 metal box bolted to the passenger side fender between the solenoid and the fire wall. most likely that's your problem

jdinner

With a test light, connect the clip to the negative post on the battery. With the probe, make sure you have the test light light up when you touch the BAT terminal of the alternator. With it running, it should also light up on the F (FLD) (Field) terminal of the alternator.
My guess is that it is not.
Locate the Voltage Regulator (4 wire box) The "I" terminal is powered through the ignition switch and through the dash bulb. If that ALT bulb is burned out it will not charge.

RustyTruck

Thanks for all your replies. I'll do everything listed.
I've been working on it for a couple summers. Once I fix something, something else goes out! Haha
But I'm almost to the point where all the mechanics have been replaced or fixed.

Johnboy429bbf

just keep chasing those grimlins. even if you gotta step away for awhile. it'll pay off. I go thru this every spring with my pulling truck. chasing all the problems I crated the summer before

RustyTruck

Yeah, I can't give up on the truck. If I'd abandon it now it'd be too much of a loss. After I fix the electrical problem Ican finally start dgoing cosmetics.