I have a 1 wire on my 71 cutlass. The first one i had worked for about a year and it worked ok but there were issues with the volts jumping at idle from 14 to 16v but and when the fans were on it would drop to 12v. That one burned up a week ago and I put a new one on and it seems to work fine when first started the after a little while it drops to 12 v and with the fans its only 10v and highway speeds it jumped from 14 to 18v. I looked at another thread and found a diagram on how to bypass the external regulator. Right now I have a jumper wire from the battery power on the alt. The the #2 terminal on the alt. Should I rewire it to the 3 wire bypassing the external regulator?

 

Once again, why? Here's something to consider: GM, who is always trying to shave a few pennies off the cost of building a car, NEVER made a one-wire alternator. There MIGHT be a reason for that...



Do you somehow have the external regulator wired up now?

Most one-wire alternators have a regulator with internal jumpers, so simply connecting the other wires may not do anything. At a minimum change the regulator for a conventional three-wire one before making any wiring mods. Then, wire it this way:

 

Buy crappy Chinese product, get bad result.

Buy crappy Chinese product again, get bad result a second time.

Advice: Refrain from buying crappy Chinese products and don't try to second guess perfectly good engineering designs.

- Eric

 

The external regulator is gone. If I did more research beforehand I wouldn't of ever used a one wire but I guess you live and learn. But like I mentioned I have a wire from the #2 terminal on the alternator to battery power. I think I'll try changing the regulator and rewiring it. Thanks for the help.

 

Check out "MAD Enterprises" very good info, supplies and knowledge.

 

As Joe stated with the included schematic, this is the best way to run with an internally regulated alternator. It's a very simple wiring change.

 

Today it would charge fine when it was cold. When it gets hot it only puts out 12v and drops to 10v with the fans on and sometimes will stay at 10v when the fans shut off. I don't know a lot about alternators if you can't tell. I did check out that M.A.D site and it has a lot of helpful info.