I have never had to mess with a stock alternator. The DSPO removed mine before I got the truck. But, I am going to try and use Pistolnut's 24V alternator on my M35 to replace the external regulator generator on it. The only problem is that Pistolnut said it overcharged.

So, I decided to test it on my alternator testor in my class. This is a machine that has a motor, belt and pulley along with a sliding mount for alternators. It has a bunch of wires and switches making it able to hook up to all kinds of alternators. It even has a gauge for amps and volts. The gauge only goes up to 18 volts and the console can only supply 12v.

Then I decided to hot wire it on the machine. Using the machine to turn the alternator and using a 24v battery charger for a source and a multimeter to read the output.

I put it on the machine, connected the alt ground cable to the negative on the battery charger. The positive on the charger to the small wire on the alternator. I turned the machine on and it started turning. No volts were showing at the big bolt where the big alt supply wire goes. Then, click! and the motor lugs and the speed reduces a lot. But, 2 volts were showing and the my machine couldn't turn it any faster.

I reversed the positve connections and got nothing until I touched the small wire to the big wire bolt. Same result with the load on my machine. It couldn't turn it.

My question is this:

The small wire with the Packard connector is the alt exciter that turns it on while the big wire that bolts on is the positive back to the batteries, right?

I am going to take it home and install it on the Gasser. I don't want to burn up my good Optima red top by getting my wires backwards. I will check the output if my Gasser can turn it. Hopefully, the litte hex bolt will adjust the output to what is required.

What is the required charging output?

Thanks.