One Wire Alternator High Voltage

[Torinoman]

I have a one wire setup in my Torino and I recently noticed the voltage is all over the place. Yesterday, when I started the car cold it was around 17v (jumping up and down half a volt while running) and once it warmed up, it was still around 15-16v (again, jumping around, not showing steady reading). If I turn on both 30amp electric fans I can load it down to 14.5v.

Without the car running the battery shows 12.85 volts at the terminals and 12.85v at the solenoid (battery is in the trunk). With the car running the voltage at the battery is a steady 14.8v.

After playing around with connections and measuring voltage in different places and what not, I feel like the alternator internal regulator is going out. Could it be something else?

Can the internal regulator be replaced easily? I think its a PowerMaster GM 10si.

If its time for a new alternator, does anyone have an affordable recommendation for a high amp (need about 140amp) one wire alternator? I found that summit offers one for $127 (link), but it only carries a one year warranty. Is there a part store alternative that has a longer warranty?

Thanks

[FastFox]

Can you take yours to a good repair shop and have it repaired ?

[svauto-erotic855]

One wire alternators are always a mistake. Just get a regular Ford 3g and be done with it. I bought one last year that was all US made with new parts and it was a touch over 200 bucks. If the wiring is intimidating for you I will gladly give you a hand and have all of the materials needed. You can also just get one for a V-8 Mustang or Taurus from any parts store and they will work just as well.

Mine came from here. Make sure to get the plug if you order it.

https://alternatorparts.com/ford-3g.html

FYI: A single grove pulley can only support the production of about 90 amps before it can no longer turn the alternator and the belt slips. Going with a larger OD pulley helps a bit but there are still limits. This is why I used to love the small case 90 amp 3g from Ford Motorsports for swaps onto 60s vintage cars but sadly it was discontinued.

[Torinoman]

Can you take yours to a good repair shop and have it repaired ?

Thats an idea I hadn't considered. A quick google search shows a place nearby that I could try.

One wire alternators are always a mistake. Just get a regular Ford g3 and be done with it. I bought one last year that was all US made with new parts and it was a touch over 200 bucks. If the wiring is intimidating for you I will gladly give you a hand and have all of the materials needed.

Mine came from here. Make sure to get the plug if you order it.

https://alternatorparts.com/ford-3g.html

Its not that its intimidating, but this setup has worked for 10 years, why rock the boat.
Also, all those units are $230-$500, with the exception of the unit built in china.

Guess I'll try the rebuild first, unless anyone has reason to think this maybe unrelated to the alternator.

[Fourx4Brad]

local shop in Richardson

I've gone here several times over the years with good results.

Richardson Generator and Starter
208 N Greenville Ave
Ste 101
Richardson, TX 75081

https://www.yelp.com/biz/richardson-generator-and-starter-richardson

.

[Tx Redneck]

https://www.google.com/search?q=hammond+brothers+garland+texas&oq=hammond+brother&aqs=chrome.2.0j69i57j0l4.6414j0j7&sourceid=chrome&ie=UTF-8

Has always been the go to round here.

[svauto-erotic855]

Thats an idea I hadn't considered. A quick google search shows a place nearby that I could try.



Its not that its intimidating, but this setup has worked for 10 years, why rock the boat.
Also, all those units are $230-$500, with the exception of the unit built in china.

Guess I'll try the rebuild first, unless anyone has reason to think this maybe unrelated to the alternator.

The second one down on the list is what I used. I personally like using the yellow/white wire for remote voltage sensing on Fords and not being able to do so is what I despise about 1 wire alternators.

F1-3G-HD140 $239.95

Your problem is without a shadow of a doubt caused by the alternator but you may want to double check your grounds. Any rebuild shop can fix it in not time flat. I used to use a place in Grand Prairie called Alterstart and they can do stuff while you wait if you don't get there at lunchtime.

[Torinoman]

Can you take yours to a good repair shop and have it repaired ?

The second one down on the list is what I used. I personally like using the yellow/white wire for remote voltage sensing on Fords and not being able to do so is what I despise about 1 wire alternators.

F1-3G-HD140 $239.95

Your problem is without a shadow of a doubt caused by the alternator but you may want to double check your grounds. Any rebuild shop can fix it in not time flat. I used to use a place in Grand Prairie called Alterstart and they can do stuff while you wait if you don't get there at lunchtime.

I'm not DFW mustangs ballin out of control, $240 was way more than I wanted to pay right now.

I've been to Alterstart a half dozen times. I've run their starters and alternators, but I've found they don't always stand by their products. I had a high amp alternator from them for a 7.3 SD go out after about a year. I had to really fight with them to get it repaired and I still paid part of the repair.

Anyway, I dropped it off at Richardson Generator this morning. We'll see what happens.

[Torinoman]

UPDATE: Put in the repaired alternator, started it up and its still making 15.5-16v at idle.This was with the engine and battery dead cold, and only the ignition on as a current draw. I didn't have time to let the engine run and warm up.

Should it be a bit higher when cold? If I try again and let it warm up should I expect it to drop down, or am I probably still chasing the root of the issue?

[JV106]

You checked it with a multimeter or you’re going off the gauge?

[Torinoman]

Multimeter

[JV106]

I was thinking maybe your gauge is off. But I guess not. Maybe haul it to autozone for testing before and after taking it back to the guys that repaired it.

[Torinoman]

Well i already took it to the place for repair, so I don't have a before to compare it to.

I guess i can take it off and take it to autozone and have them check it

[JV106]

That’s what I meant. Take it there now if it tests bad haul it back to the repair shop and see if they’ll stand behind their work. Then I’d get it tested again after they repair it to make sure it’s really fixed.

[Torinoman]

Right on. I'll try that