2nd bad Powermaster alternator

[PeteyDaMan]

Guys,
I must be cursed lately.....
A few months ago my Powermaster 1 wire alternator (75091) started having a parasitic draw that would kill my battery overnight. I was 5 or 6 years old so I figured I would just replace it
I bought a new one just about a year ago and maybe has 500 miles on it
I just pulled The Beast out of the garage to go to the local car show and it was over charging to the tune of 17 volts at 3k rpm
I immediately turned around and pulled back in the garage. I pulled the battery cable for a few to see if it reset/fixed the issue but once I cranked the engine back up it slowly crept up to 16 volts

Now I know people are generally happy with Powermaster products but having been burned twice I'm looking for another brand of 1 wire, V groove, 100amp alternator

Any suggestions are welcome (except for people telling me to put a traditional 3 wire with external regulator in...that ain't happening)

 

[multimopes]

I had a 75 amp Power Master which worked fine but didn't supply enough juice for my 2 electric cooling fans. The fans draw 30 amps each when running & 40 amps when they start. At idle I was discharging slightly with one fan. It was recommended to try a unit from (TuffStuff). They are made here in USA (supposedly) and I ordered a 125 amp unit. They are supposed to supply enough juice at idle . Although it's a nice piece, at idle I am still barely holding it with one fan but when the second kicks on, I am down to about 11 volts. I have to step on the gas to raise the idle speed to around 1200 before the charge is better. I wish I had a factory style mechanical fan and shroud but time & usually empty wallet syndrome prevent those things. By the way, mine are not 1 wire!

 

[64 Sportfury]

I had a new Powermaster one-wire go bad just within the 90-day warranty mark last year. It was on my daily-driver 68 Coronet wagon. If it had been on a vehicle that got less usage, I might've been on the hook for a new one. Summit Racing took care of the replacement. It was mentioned to me that the quality of the internal voltage regulators had diminished.

 

[PeteyDaMan]

I'm thinking of going with the Proform Parts 440-472
Anyone have experience with this one?

 

[Jerry Hall]

Thread '1 Wire Alternator' FOR SALE - 1 Wire Alternator

PM me with offer.

 

[wish4hemi]

I'm thinking of going with the Proform Parts 440-472
Anyone have experience with this one?

Install article: Gallery: Vying For Voltage With A Mopar 110-Amp One-Wire Alternator - Mopar Connection Magazine | A comprehensive daily resource for Mopar enthusiast news, features and the latest Mopar tech

 

[Geoff 2]

I had a 1 wire mini 50 amp alt drain the battery overnight. I 'fixed' it by using a 60 amp solid state relay in the alt cct; the relay was triggered by engine oil pressure. Engine off, relay disconnected the alt from the battery.

 

[69a100]

Note to self: Don't buy a Power master alternator!

 

[6PKRTSE]

We buy thousands of their alternator and starters per year. It is amazing how many we send back that they diagnose as the customers car was wired incorrectly and causing to much draw or if it has carburetor. The engine back fired and kicked the engine backwards blowing out the bendex of the starters. However, they do repair sometimes on our dime or sometimes they repair at no charge. Depends on each individual situation and age of products.

 

[PeteyDaMan]

We buy thousands of their alternator and starters per year. It is amazing how many we send back that they diagnose as the customers car was wired incorrectly and causing to much draw or if it has carburetor. The engine back fired and kicked the engine backwards blowing out the bendex of the starters. However, they do repair sometimes on our dime or sometimes they repair at no charge. Depends on each individual situation and age of products.

If i were using old wiring I might consider it's being caused by something shorted or wrong but every stich of wire from the front to the back of the car is new using an America Autowire kit. It's a one wire charging system running through a 175 amp mega fuse kit and nothing else is having issues.

 

[69a100]

I take you don't have another known to be good alt. that you can swap out? How many amps do you need or want? You might have great luck going to the bone yard and get one and be done with it? Just spit ballin. Good Luck

 

[68 Sport Satellite]

I've been running a Powermaster 3 wire alternator for 5 years with no issues. Is it just the 1 wire alts that can be problematic?

 

[PeteyDaMan]

I've been running a Powermaster 3 wire alternator for 5 years with no issues. Is it just the 1 wire alts that can be problematic?

I'm guessing so since the issue with both of mine were in the voltage regulator and the diodes

 

[ykf7b0]

Looks to me you have a bad voltage regulator. I have never had a Powermaster go bad in the past 20 plus years I've owned them.

 

[PeteyDaMan]

Looks to me you have a bad voltage regulator. I have never had a Powermaster go bad in the past 20 plus years I've owned them.

you are correct, but the alternator is a one wire with an internal regulator

 

[383man]

I am running the 100 amp Power Master one wire alt that is a Mopar alt that they build with an internal reg and I have it on my 63 Sport Fury. In 2 years twice the internal reg went bad and it stopped charging. I know it was the internal regulator as I jumped it out and the alt worked good. Well the first time it was still under warranty and they sent me a new one 7 months later it went bad again and they said its out of warranty and I will have to pay shipping and parts. I said no thanks and just changed the brushes so both are insulated field brushes and I wired my external regulator back into it. Been working for about a year now like that and still puts out up to 100 amps and no bad regulator now. Ron

PS - Its easy to test the alt and bypass the internal regulator. If its the internal reg like mine has had go bad you can wire the external reg in like I did.

 

[383man]

I've been running a Powermaster 3 wire alternator for 5 years with no issues. Is it just the 1 wire alts that can be problematic?

Thats the only one I have had trouble with. My son also runs the same PM one wire alt and his has been fine but my internal reg went bad twice. Ron