Voltage Regulator

[Fr Mike]

As an update, I took the  P2's generator & regulator to
a trusted re-builder for bench testing today. Needed repairs
were estimated in excess of $100.

So, in the interest of economy and reliability, I bought a tested, re-built, 6 volt, positive ground,
one wire alternator for $60. These units are popular at the Iola Old Car Show here (Wisconsin)
and elsewhere. They crank out about 7.5 volts and 32-35 amps. And, the price is right!
Will keep the stock generator, regulator, and bracket with the car.

Thanks for replying to my "cry for help"! Your informative replies on the forum have been very helpful and are stored away for future reference.

[TodFitch]

The Ford Model A was a 6v positive ground system (I think all Fords were positive ground) so the alternators sold for Model A's should work electrically. I don't know how easy they would be to fit mechanically.

====================

In response to a question emailed to me directly:

The cutout is simply an automatic switch to disconnect the generator from the electrical system when the engine stops.

You want the current rating on the switch to be high enough. Its like a hydraulic jack: You can use a 10 ton rated jack to lift a 4000 pound (2 ton) car. But you sure don't want to use a 2 ton jack to lift a 10,000 pound (5 ton) truck.

So the cut out section of the P4, P6 and P8 regulators are rated higher than the cut out section of the P2 regulator. That is okay. So you should be able to use a P4, P6 or P8 regulator on a P2 generator. However you should not use a P2 regulator on a P4, P6, or P8 generator.

[John Hendricks]

An acquaintance who is into Model A's told me that 6v alternators have been available for sometime for 6v A's.  I don't know if they are pos ground.  I figured I would check into it when the 3rd brush gen on my PB shucks out.  But like a timex, it keeps on tickin'.

[Fr Mike]

Again, thanks for your helpful input, Ted!  I'm going to remove my generator with the regulator for bench testing this evening, and will see what it is. If the regulator (and/or generator) can't be (professionally) adjusted or rebuilt satisfactorily, your recommendation sounds like a good "plan B".

As long as we're talking about a possible modification, the thought of a 6 volt alternator with headlight relay has crossed my mind too (???).

[TodFitch]

My 1936-42 service manual shows the regulator for the P2 to have a number TC-4301-A stamped on it. That is the only car from 1936-42 that uses that particular regulator. My 1933-36 repair manual does not list the regulator numbers but I doubt that the 1934 used the same regulator as they did not start using Auto-Lite until 1935.

That being said, you can probably make an arbitrary two stage (voltage and cutout) regulator from a GM or Chrysler Corp setup work (for Chrysler that would be 1933-39) as long as the regulator works by grounding the field wire. The later ones would have higher current carrying capability and would be safer (the P2 was rated at 21 amps the P4, P6 and P8 were rated at 30 amps). You won't get any more current out of the generator (that is set by the third brush) but you won't be over stressing the contact points on the cut out portion either.

[Fr Mike]

Tried them all and more, with no luck. Looks like the unit was made only 3 years ('34-'36). Kind of scarce. Apparently there are no reproductions being made either. Am am now looking at pulling off the generator, with the regulator,  & having them  bench tested & adjusted (or rebuilt, if needed).

Was is in Germany twice last year, mainly the south. Enjoyed it immensly. What a beautiful country!

Thanks for your input!

[Go Fleiter]

Did You try the usual suspicious?  Bernbaum, Kanter, Neil Riddle, Pro Antique etc.? If You need Adresses let me know! Do You know Hemmings monthly?
Greetings ! Go

[Fr Mike]

Anybody know where I can get a voltage regulator for my '36 P2?  Desperate in Wisconsin!