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Beginning the process of proving that battery is not being charged, and finding and fixing the cause. Replaced alternator probably 5 years ago; do remember there were issues with using existing wiring harness with new alternator, like what wire went where and to what, why an alternator needed THAT many wires, etc. Have long suspected that alternator wasn’t charging battery, but because truck is project and hobby only and not a daily driver, haven’t gotten back around to deal with it til now. After doing a lot of work on different systems recently, I ran the truck 2 hours or so in a single day, and was lucky to get engine to start last 2-3 times (fits of slow turning over with pauses). Probably will start by replacing voltage regulator, but I’ve heard that the system often has a “fusible link” somewhere in the system; do these pictures show recognizable fuses or parts of the charging system that should be looked at? Appreciate it very much, thanks! Will get a picture of back of alternator in a day or two if that is helpful. Sorry for the tangle of wires…
If you have a decent autozone around, they can test the alternator. I'd search online to see if there's any test procedures for a voltage regulator before buying one - but if I had an extra voltage regulator sitting around that I knew was good, I'd try it.
My truck has one fusible link that I know of, and when it blew, I didn't have power to crank the starter - the whole truck was dead - although I didn't think to try the horn, which gets its power independently from the fusible link.
I went through this many years ago on my old 1968 Cougar, ruining its alternator by trying to take it apart to rebuild it, (bolts broke off) and then finding out that it was the voltage regulator which was bad, after putting another alternator in it...
The old style voltage regulators use contact points which can wear, corrode, or get stuck. Newer ones from the early to mid 1980s on, are more 'solid state' with no moving parts.
If you have a decent autozone around, they can test the alternator. I'd search online to see if there's any test procedures for a voltage regulator before buying one - but if I had an extra voltage regulator sitting around that I knew was good, I'd try it.
My truck has one fusible link that I know of, and when it blew, I didn't have power to crank the starter - the whole truck was dead - although I didn't think to try the horn, which gets its power independently from the fusible link.
I went through this many years ago on my old 1968 Cougar, ruining its alternator by trying to take it apart to rebuild it, (bolts broke off) and then finding out that it was the voltage regulator which was bad, after putting another alternator in it...
The old style voltage regulators use contact points which can wear, corrode, or get stuck. Newer ones from the early to mid 1980s on, are more 'solid state' with no moving parts.
I went to one auto parts store that said you can’t test alternators while they’re on the vehicle, and another that said you could and that it was charging. The voltage regulator looks pretty modern, but the interference capacitor under it, and the wiring looks a thousand years old. Do you recognize any of the arrowed elements shown in the pictures?
I went to one auto parts store that said you can’t test alternators while they’re on the vehicle, and another that said you could and that it was charging ... etc ...
Depends on test tools they have. We had one at my Advance would test the whole charging system on the vehicle.
30 plus years ago I discarded the OEM mechanical regulator on my '77, plugged in a electronic regulator intended for a mid '80s F-150 as I recall, been perfect ever since. Just added a new volt meter Saturday, a real volt meter through a relay.
Depends on test tools they have. We had one at my Advance would test the whole charging system on the vehicle.
30 plus years ago I discarded the OEM mechanical regulator on my '77, plugged in a electronic regulator intended for a mid '80s F-150 as I recall, been perfect ever since. Just added a new volt meter Saturday, a real volt meter through a relay.
ill add a hamster excercise wheel to not have this problem anymore. If the alternator and voltage regulator are good, that probably means wiring, which means an infinite nightmare of 30 plus wires, what they do, where they go, which is the problem, and how to know that. I’m hoping someone out there can identify the pictures with the yellow arrows, though. It would be nice if the problem is just a fusible link burned out…
Get a multi meter or a load meter and check it in the truck running. If you don't have a meter, see if it will stay running while you remove the positive terminal from the battery for a moment.
