gm single wire alternator

ok i have one on my 61 on a sbc and the damn thing wont charge anymore than 12.85 volts what gives

 

put a voltmeter right at the stud on the back of the alt- if that's all your getting......well,sorry- you have alt probs.

 

yeap tryed that at higher rpms and the gd thing still only put that much out...soooo how do i wire a normal 3 wire

 

There is a different regulator for the 3 wire, I think. you'll have to change that by removing it from the back case. There is a 2 prong plug that connects to the regulator and one of the terminals is the sensing wire and goes to the ign. sw. "on" terminal, if I remember correctly.

 

well the old one was a three pronger so i got all the old wires

 

i cut it all out thinking this single wire would be better

 

No help here on a three wire hook-up,but i've seen diagrams on the HAMB before explaining it in detail. I have nothing that uses factory wiring anymore,but, with a one wire,you should be getting AT LEAST 13.4V at the back of the alt!,if not more! All depends on =where you got it,was it a converted unit,was it tested.... Prob is just the alt itself. If you have an alt/starter shop,they'll test it,and tell you what it puts out. Don't bother with parts stores.
You might be looking into an upgrade with your existing piece.

 

Go to www.madelectrical.com

more info there on alternators than you'll ever use.

Terry

 

or you could just go buy a new one wire alternator too.

 

Some single wire alts need to have the RPMs raised to get the alt. to start charging(mine was about 1300 RPMs). You may be just reading battery voltage. Start the engine, bump the RPMs up to about 1300-1500 RPMs and then do a voltage check. If that's the case, everytime you start the car, remember to inc. the RPMs to the kick in the alt.

 

Things to think about when swiching to a one wire alternator replaced 2 computors in a Holley injection unit I went back to a 3 wire. My buddy put a crome one wire from summit on his 61 chevy and lost his radio one day looked at his volt meter an it was stuck in the peged out position.

 

I think the chrome retains alot of heat. I prefer to ploish mine. they are aluminum.

 

That's just the beginning of your problems when you run a 1 wire alternator.

If going to a 1 wire alternator was "the greatest thing since sliced bread", don't you think GM would have done it???

 

I've had a GM 1 wire on my 55 Ford since 2008 when I converted from 6volts, and it works fine.. maybe other issues with your set up ?? just MY opinion...

 

I think Waddaycare is dead on right. Never been a fan of them myself.

 

If you must use a one wire alternator ask the manufacturer for the output at idle - this is where it is needed most but put out the least. Think about it as you are stuck in traffic in your ProFairgrounds 1200hp fire breathing monster megabuild with the three zillion watt stereo and a/c cranked up all the way....

 

I had issues with my new one wire alt., wouldn't read over 13 volts on the voltmeter. I found I had two real poor ground connections. Fixed both, works great now. check your grounds. Hope this helps.

 

I have one wire units on all my cars and they are flawless. Then again I always relace the entire electrical system also. Like hammeredabone says, a good ground is critical for the operation of the unit.

 

With all of the nice powder coated brackets and nicely painted engines it is easy to lose ground. I make up a seperate pigtail wire and install it on one of the rear case screws and run it down to either a known good chassis ground or tie it into the braided ground strap that connects the engine to chassis ground. Alternators need proper cooling and a solid ground to live a long life.

 

My daily, a '63 Chevy C10, had a 1-wire alternator on it when I bought it 3 or 4 years ago. Operates great with no problems.

 

Been running one on the '58 for years without any problem. Last year a buddy gave me a "bad" chrome unit, I had the local electrical rebuilder test it and found the voltage regulator was bad. A quality replacement VR was $15 and took about 20 minutes to swap out. 1500 miles later it still works great...

 

If you think they're so good then answer the question V V V

 

The opinion that if it was best the factories would have done it already is completely wrong in every way. The factories put out an adequate product spending the least amount of money possible. The aftermarket people are behind all of the best modifications for preformance, mileage & reliability, the factories incorporate these items years after.
If you actually know how an alternator works, the step by step diagnosis is easy. Most suggestions so far are right on track, the problem can only be caused by a few things.

 

i've never understood the appeal of a one wire alternator. one wire, two wires, three wires, you still have wires running to it. if you tidy up your wires they look good and work better (in my opinion) with the factory 3 wire wiring.

 

Just saying both cars never had a problem with 3 wires. If you have electronics think twice about a one wire.

 

Why is it that, some think 1 wires are better ?
Is it you, do not know how to wire it, or do you think it is more durable.

Finding a quick replacement for a one wire, will be tuff when on the road, Because your wire harness has no connection for the OE replacement Alt

 

Take it to a local auto electric and bench test it,mine tested OK at an Autozone but was not working well installed also low output, had to replace stator and also converted it to a two wire so it would charge off idle instead of revving to 2 grand to "excite" the internal regulator.

 

A friend of mine bought a wrecked Chevy police cruiser from an auction, and gave me the Hi-Amp alternator.
Put it on my F100, (350 Chev power, dependable) but the thing charged 15.5 volts on the Voltmeter. Constant.

Recharged battery, (13.1 volts static charge) then started the truck and rechecked:
Battery at fully charged state, alternator still charging 15.5 Volts at gauge.

Replaced regulator with single wire. Installed alternator, started it up and: 12.9 volts on Voltmeter. Raced the engine, 1800 RPM, gauge went to 15.5 volts again!

Checked, scraped, tightened, and meter-checked every ground connection: still 15.5 Volts.
It's like there's an open power grid somewhere!

Truck has been fine since 1974, no problems...but I should install a Rebel kit to 'clean' the wiring up...It's the only thing that hasn't been analyzed wire-by-wire, but there's no standard 'test' I haven't tried.

I HATE the 1500 RPM rev I have to do every time I start it...my megaphones under the rear axle draw much attention. LOL

 

Pretty much any decent parts store in the country has one wire alternators as well as Advance, Auto Zone, etc.

 

Just make sure you know the part number because they hate looking it up!