I'm looking to replace a 6V generator with a 1 wire 12V alternator. I'm trying to figure out if a GM or Ford version is the way to go. I am putting it onto an L134 4cyl Willys/Ford block. I will be using a "universal" bracket to attach it to the block, but would appreciate input as to which would best suit this application. I see GM ones quite frequently on other's conversions, but am curious if there's a reason for the GM vs Ford choices on these somewhat "generic" alternators. Also, I've seen on one video the need for a voltage reducer (I forget the name) when the alternator produces a higher amperage than what the gauges are designed for. Any idea what I should be looking for if I get one of these generic alternators? Should I get the common type (GM in 80-100A) and get gauges that are rated for that power? Thanks in advance for your assistance.
Amp wise, you need what the systems on your car demand or will demand when you have it together the way you plan to have it in it's "done" stage. Personally I don't see the reasoning for running a one wire over running a regular 10 or 12 SI Delco or running a Ford alternator. Most of the easy to use Ford alternators hot rod wise are external regulator alternators though. If you are low buck and have a decent 10 or 12 SI alternator sitting on the shelf you can buy the one wire regulator kit off Ebay pretty inexpensively. Or just wire in a diode you can get pretty cheap and run the exciter wire and bag the one wire nonsense. Car wise it is the street rodders who don't want wires showing that picked up on the one wire thing from the farm equipment anyhow.
Thank you for the detailed reply, I guess I've just been on a YouTube journey watching people wire in 1-wire alternators (for simplicity more than likely) into trucks, Jeeps, and old cars. I have a reproduction wiring harness, so I am trying to limit the amount of extra non-original wiring in the engine bay. This might be just a temporary thing while I learn to rebuild the generator for a full restoration. The engine is a Ford built engine, but its in a Willys body. The videos I've seen didn't specify why they went with the GM style alternator (1-wire) instead of a Ford style alternator (also 1-wire), so I was unsure if there was really a reason outside of most commonly used.
I used either a 10 or 12 Si alternator in my ‘42, don’t recall which, but used madelectrical to wire it up. I had to add a light, light would be on until maybe 1000 rpms, the the alternator would charge and the light went out. I’m thinking it turned it into a 1 wire alternator on the cheap, as I had one stashed.
I would suggest reading through the Tech Articles over and MAD Electrical: http://www.madelectrical.com/electricaltech/onewire-threewire.shtml
Since you need to use a universal bracket for that engine, it’s not going to matter which one you use. Majority of the reason to use the Ford version is to fit a Ford vehicle. FWIW Vintage Auto Garage may have a fitted bracket for your engine
Having seen how 1-wire alternators can undercharge and more painfully overcharge, wire in the 3-wire alternator! Otherwise you'll end up with it hitting 15V from time to time and burning out Pertronix kits, damaging batteries prematurely, and all kinds of other issues. Its so easy to wire one up properly, there's no need to deal with the 1-wire mess. Easy is problematic in this case!!! BTW, I REALLY like Mechman alternators if you want one that'll live through all the worst demands and will never overcharge!
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