I am cutting my teeth, mechanically speaking, on a 1962 F100. So far it's been pretty great however I can't seem to get the charging system right. My battery keeps running down and when running the battery doesn't measure across the terminals at anything higher than when it's off. I recently replaced the alternator and am sure I put all the wires back the way it was. I've had a hard time finding documentation, youtube videos, or even mechanics in town who can tell me if the wiring is correct. I am hoping someone here can point me in the right direction or might know of a resource I can use to figure it out myself.

I've included some pictures that might help. Any help you can provide is much appreciated.



yellow/black wires running from the alt into the horn relay and the voltage regulator (which I dont think is necessary).





better pic of the wires





back of the alt. Yellow wire run up into the solenoid.





profile of the alt





layout under the hood





give you some idea of what im working with

 

Not the stock charging system. Throw out any concept of using stock truck service info.

That is a GM alternator. Your truck originally had a generator. Common swap, but I can tell already your setup will not work.

I'll edit this post after I find some good info on this swap for you.

Here is a good place to start;

http://www.oldengine.org/unfaq/10si.htm

If you research GM 10SI alternator swaps, you will sooner or later run into the one wire alternator. Tempting as that sounds, please read this first;

http://www.madelectrical.com/electri...hreewire.shtml

Your installation is already pretty well butchered. PO got the alternator mounting right and I think the yellow wire to the back of the alternator is correct. As you suspect, none of the regulator wiring is required and it looks like much of it is missing. Disconnect the wiring, tape the ends so nothing shorts and remove the regulator.

Even though the yellow wire makes the electrically correct connection, your old wiring might not be up to the higher output from the alternator. This may be even more so if your vehicle is equipped with an ammeter. You should be OK as long as you don't start adding monster stereos or other high current demand equipment.

The GM alternator was made in external and internal regulator models. Yours seems to be the far more common internal regulator 10SI. Difference is in the 2 wire connector where you presently have a jumper. You can remove that jumper and throw it away right now, it does nothing! External regulator models have the terminals arrange parallel to each other , (II), internal regulator puts them in line, (--). One wire alternators are common in marine applications and like the article referenced, are not the best in automotive applications. Best practice is to run the #2 terminal right back to the battery post. It's job is to reference the state of charge in the battery and that is the most accurate place to make that measurement. The #1 wire turns on the alternator output. It requires switched battery + from the ignition switch and also can drive a charge indicator lamp. If you can locate the wire on your old regulator that went live with the key, this is the correct wire to run to the #1 terminal on the 10SI. A note of caution on this wire as it was designed to feed power back to the charge indicator lamp, it will also power up any other equipment connected to this feed. The lamp was supposed to limit the current that can be backfed, but it will work just fine hooked directly to switched 12V batt +. Problem is, so is your ignition coil and this will supply enough power to keep your ignition on and the engine running, even with the key off! 3 possible solutions, 1), use a charge indicator bulb in series between the ignition switch and the alternator #1 connection, 2) use a diode in series with the #1 connection. (This is polarity sensitive), 30, use an ignition switch which isolates the ignition coil feed from all other 12V feeds when turned off. i.e. IGN 1 and IGN 2 on your switch. You can also accomplish this with a relay.