alternator

I'm thinking of converting my S-150 to an alternator. (Don't beat me up too bad! ) The current system is not charging at all. At this point I have not looked into whether it's the generator that's not working, or the regulator, or both. I'm thinking that it would probably be cheaper to just convert it. "Correctness" is not a concern for me--I just want it to be a reliable driver. The truck is already 12 volt.

Just wondering if anyone has done this and if there are any wiring diagrams out there. I'm thinking just the standard Delco 3 wire alternator. Also, it would be nice to keep the idiot light on the dash if possible.

Thanks!

You just need to make a bracket to hold it in line with the fan belt,

Rest is just wires, I had a truck with GM single wire alternator,

Hardest part is the pulley, if you have the original fat fan belt, sometimes you are lucky and genny pulley will fit your new alternator, sometimes not,

There are alternators "hidden" inside original looking generator bodies available too, I think speedway has them

A bracket from a BG series engine should work. Or at least I hope it will, because I recently pulled one at a wrecking yard. There are “universal “ brackets out there for about $50.

Speedway or Jegs will sell you a new wide belt pulley for your Delco 10/12SI alternator for about $20.

On a three wire alternator I’d connect the output and voltage sense wires to where the “BAT” lug on the regulator is now, minus the regulator of course. The other wire goes to the accessory or ignition terminal on the key switch.

If using a one wire model I’d connect it to that same “BAT” lug location. Other opinions may vary and wars have been fought.

Just a thought- before going to all the trouble, are you sure the generator has been polarized? If not it won’t work.

A vise, a drill, and a piece of strap makes the bracket?
Don't get me started on "one-wire" alternators. It's like saying "jumbo shrimp". It's an oxymoron.
No matter what, there's a GROUND ckt to consider that might need to be augmented with a ground strap since our old, rusty stuff doesn't ground very well, anymore. C'mon!
I've included some mostly integral regulator wiring diagrams off the net at random, mostly GM.
For sanity's sake you usually need THREE visible wires at an integral-regulator alternator: heavy output wire to battery, battery "sense" wire to integral regulator and the wire that feeds the idiot light that isn't so idiotic.
Stay away from Chrysler Corp. alternators because they have used any number of internal wiring scenarios. They often are "isolated field". If you are a MOPAR nut you already know the drill.
I've used old Japanese alternators. It's just more work.
Leave the "idiot light" ckt off at your own peril. I'll let you learn that lesson on your own. And it isn't just about knowing if the thing is charging.
The FIRST thing I think when I see or hear "single-wire alternator" is "a dumbass is talking about JUNK".

Good point on the ground. It is assumed to be there but is often inadequate, or missing entirely. What most people don’t realize is that a 100A alternator at full clip requires 100A to flow through the frame, engine block, and alternator housing… or through a corroded cab ground, the choke cable, and the carburetor. Yikes! Ground that thing with a separate cable!

I mostly agree on the one-wire alternators. Not sure they’re junk exactly, but not what I’d prefer to use on a vehicle with lighting and accessories running through a long wiring harness. The remote voltage sensing feature of the 3-wire version is a great design. To me the one-wire version is a cop-out that leaves some performance on the table.

The idiot light is nice, too. Doubles as broken fan belt indicator.

If making a homemade bracket use the thickest material you can manage, plus grade 8 bolts. And brace both ends of the bottom mounting point! Otherwise you might discover that the alternator wobbles back and forth at certain engine speeds until one of the bolts holding it on fatigues, and then you’re stuck on the side of the road (instead of on a road trip) with a sheared-off bolt stuck in your engine block. Random example, right? Right! The idiot light would have come in handy for whoever did that.

In lots of cases the "idiot light" is what kills the ignition and shuts of the engine. Alternators are self-energizing. When you rotate the key to "off", the idiot light uses up that last little piece of energy in the alternator field. Decide to run without the "idiot light" in the circuit and you might have engine "run on".

Yeah, interesting point. I can see how that could happen depending on how the switch is connected.

I have a six volt S-120 and finally relented and and switched to a six volt alternator. Very reasonably priced at Brillman and works much better than the generator . Stickman 207

I was looking at those. Did you keep with positive ground or switch to negative? I’m guessing it’s a one wire model? I couldn’t find a 3-wire version.

It was a one wire and I kept it positive ground. Had to fabricate new brackets. - Stickman 207