[JSchmitz]

There HAS to be a difference somewhere. What about the positive wire that you ran from the alternator to the positive terminal block? Check it for continuity? Did you use the same wire on the '62 and '64?

[johnta1]

The voltage never varied from battery voltage (approx 12.3vdc with only ignition load) no matter where I checked it. This is full time battery voltage as you can see. An "0"ga cable at one point was run from the alternator to the negative post of the battery. As for not installing the drive belt I'll admit I'm old and do forget things but even I would not forget to install the belt on 2 different alternators. The only thing different I did to get them to charge was run a battery sense wire and a ignition exciter wire. I've had 3 years of college level electronics and worked as a mechanic (including working for Pontiac) for 30 years before retiring. I consider myself an intelligent person and I have no idea what caused the problem.

I meant no disrespect on my 'belt' comment. We (I anyway) don't know what knowledge you have or experience. Sounds like you have a lot!



I would add that try turning the headlights and as much power on. Sounds like the alternator thinks it doesn't need to charge?

[stellar]

This one is for Bob.

[JSchmitz]

Originally Posted by stellar

This one is for Bob.

Or Rod

[johnta1]

I would add that try turning the headlights and as much power on. Sounds like the alternator thinks it doesn't need to charge?

Another test maybe run the alternator wire to a power post inside the car, like a radio connection or fan switch. (not in addition to the original connection all by itself)

The voltage would be lower there probably and maybe make the alternator sense that it needs to charge?

[JSchmitz]

If he's measuring 12.3v it should be charging correct?

["QUICK-SILVER"]

Originally Posted by johnta1

Another test maybe run the alternator wire to a power post inside the car, like a radio connection or fan switch. (not in addition to the original connection all by itself)

The voltage would be lower there probably and maybe make the alternator sense that it needs to charge?

Voltage now that it's charging would tell the regulators min charge rate.

Could be real low since the alts were built for battery maintenance only.

Clay

[punkin]

Originally Posted by JSchmitz

If he's measuring 12.3v it should be charging correct?

I don't have any practical experience with 1-wire alternators but 12.3 doesn't sound like a battery being charged. I thought a B+ when car runnng and alternator excited, it should be up around 13.8-14.2

Sorry, hope I didn't derail the exchange here.

[JSchmitz]

Originally Posted by punkin

I don't have any practical experience with 1-wire alternators but 12.3 doesn't sound like a battery being charged. I thought a B+ when car runnng and alternator excited, it should be up around 13.8-14.2

Sorry, hope I didn't derail the exchange here.

Voltage does vary. It should pretty much always be above 12.8 I would say. I think you're right about 13.8-14.2 being normal charging range. One key thing to remember here is that he is clearly seeing a noticeable difference in voltage between the two cars.

[OG68]

How about swapping batteries along with the alternator? Takes another unknown out of the equation.

[tom s]

OK,this has gone on long enough!I have a one wire on my 62GP that I put on years ago.Does anyone want me to take pics of my wires?Only issue I have found is it will not show charging until RPMs get up a touch like 1000.Tom

[Peter Serio]

Just my opinion here is a diagram which I consider to be the absolute minimum as far as retro-fit to add a "modern" 10SI alternator into an older 1960s GM car.

I would never attempt put a "one-wire" alternator on any car.
It is my understanding that those are made primarily for marine applications, that or perhaps a farm tractor.

[Goatracer1]

Like I said I converted the Delco 1 WIRE alt to 3 WIRE and it works perfectly so I will not be going back to 1 wire. I Only used a 1 Wire alt in the first place because I thought it would be easier. I used them on both my other old cars (1964 GP and 1967 GTO) because most 100+ amp alternators are 1 wire and they needed the additional power. They have worked fine for years now.