Alternator not charging -UPDATED-

[oddball]

Im having problems with the charging system in my 67 F-100 with 352. A little quick history, the truck ran fine, it sat for 2 weeks and the battery went dead. The battery wouldnt charge so I had the alternator checked and it was bad. I replaced the alternator and regulator. The new alternator is good, I had it checked. Hooked everything up and it wont charge. I tested the output of the alternator at the battery with my voltmeter after I jumped it and it starts out at around 13.5 but steadily drops to below 10 volts. I unplugged the regulator and it still didnt charge. All the wires were fine except for the ground wire from the alternator, which is in bad shape. I didnt see any fusible links. The alternator is hooked up correctly as far as I know, battery, field and ground. The two yellow wires from the regulator plug are hot, about 13 volts, I dont know if that means anything. I have a couple of pictures if some one wants to see the wires. Im sorry I know this topic has been beat to death but Im at a loss and I checked everything I found from searching.

Robert

[fordman]

since the alt was bad maybe it wasnt keeping the battery up to begin with a let the battery degrade to bad since the alt wasn't charging enough.

[oddball]

I thought about that and I know its not the best way to check the alternator output but I dont know why my voltmeter shows the voltage dropping instead of it being maintained

[bumpside]

Oddball, You said you have pictures. Post them, maybe it will help to see them.

[oddball]

Alright these are just random pics of the wiring

[oddball]

Sorry for the crappy cell phone pics, I also posted that the wires looked ok but the previous owner did do some odd things as you can see.

[oddball]

Im going to replace the harness for the alternator soon but I drove the truck like this for almost ten years before I had this problem. Somebody asked me about the grounds, the only ground wires are for the alternator and the battery. There isnt a ground in the back of the engine like Ive seen on 68 and newer trucks. My 65 F-250 was the same way. Could this be a problem? The insulation for the alternator ground is eaten up and has a crimp connector on it but the wire isnt broken as far as I know.

[kaptnkaos]

wow Oddball...

Looks like the PO was a hatchet man... it looks like he used a camp axe to do the wiring with.
Any one of those connections could be faulty and not let current get to the battery...
I had a similiar experience with my '68 CS a couple of months ago.
The connector on the heavy charging wire from the back of the alt, had sorted out and actually burnt the connecter in half.
So sometimes it would touch and make a connection other times none at all...
I would start by tracing wires and replacing the butchered ones with good wire and new connecters.
I am guessing, but I bet when you moved the wiring around to preplace the alt and regulator you caused one of those connections to lose conductivity.
Replacing the wires isn't nearly as hard as it sounds

KaptnKA S

[fordman]

i'm with you on this. it couldn't be the wiring because it worked before the problem started. the only way it could be the wiring is if the wires because loose when you swapped out the alt and reg.

[oddball]

HaHa yeah Im a sucker for buying vehicles that need tons of work, Ive owned far too many to count. Im going to replace what looks bad and go from there. Thanks for the help guys.

Robert

[bumpside]

Oddball,

The last picture, in the lower left side of it, has a wire connected with a bug( large threaded bronze connector ) The black bump where the two wires turn to one wire may be the fuseable link . With the battery disconnected, check to see if you have continunity through that bump where the two wires turn into one. Check from the single wire to each of the wires on the other side of the bump. You can use a volt meter set on 20K or a self powered test light. If there is no continunity, that is the problem. Replace the link. Or put a 40 to 60 amp fuse in place of it.

[fordman]

thats not a fuseable link. its just a connector under there. beside that kearny.

[kaptnkaos]

Hey Oddball,

At this point it seems that the only two options left would be the battery or the wiring harness.
I ended up replacing the battery, the alternator, and the regulater, because of faulty wires that looked good...
One of the alternater connecters was burned totally in half under the rubber cover...
I've been driving mine around like that since last Feb...
As long as I drove it during the day time, it was ok...
I drove it to Portland OR one Sat (130 miles away)... going down there no problems cause it was daylight.
I got about half way back before I had to turn the lights on.
I made it home fine, but the next day the battery was dead as a door nail...
it never would take a full charge after that so I replaced it...
That was back when we got the stimulus check from the gov.
I bought a new battery and have driven it all over western WA with no problem... during the day
The very first time I had to drive it at night with the lights on the battery gets drained again...
They checked the alt out put and it was right at 12v... which will run fine as long as there was no load.
When I removed the alt, I found the burnt connecter and cut the wire back to clean wire and put new connecters on it...
Installed the new alt and reg and haven't had any more problems even at night...
That's why I recommended checking all of the wiring...

KaptnKA S

[bumpside]

Kap,

I agree with you . I was just wondering about that bulge where the two wires go to one. I guess the link is under the tape somewhere, or missing then. It wouldn't hurt to make sure if it is there. And, if it is working.

bumpside

[oddball]

Thanks for the help guys. I agree about the wiring, Im going to start with each wire and go from there. I cant really test the battery so that will have to wait