specific question about voltage regulators and generator polarization procedure.

[Philosopher]

Howdy all. This is my first post, and I am trying to verify if I have the correct voltage regulator and the correct procedure for polarizing the generator on my tractor. The tractor is not charging.

I am helping my 91 year old friend get his old tractor up and running that's been sitting for a while... I am a reasonably good mechanic, and this forum has been a tremendous help -- THANK YOU!

The tractor is a 6v (+) ground 1955(?) gasoline Ford 700 series. After a new set of points, going through the carb, (and a whole slew of other things that are important to do before a fist starting an engine that has been sitting,) it's now running well, but not charging. Battery is good. I went through the wiring with a voltage meter and it all seems to be good and connected correctly. The ammeter tests good.

The Voltage Regulator tests bad; inside the VR one of the hair-thin coil wires is melted with an open circuit.

The generator has 2-brushes, and is the "externally sourced, internally grounded field" version, with endcap number OHA-10125-A. I have bench tested it as well as I can without a growler, and it now tests good. There was missing insulation from the internal Field wire near the points, which may have been shorting to ground. I fixed that and now want to repolarize the generator.

I bought what appears to be a correct replacement VR, but it appears to be slightly different from the one it is replacing.

Here are my questions:
1. Does the "externally sourced, internally grounded field" generator require its own unique voltage regulator, or does it share a VR with the "internally sourced, externally grounded field" generators? They both look about the same, but the terminals are not all in the same order.
2a. I see there are different generator polarization procedures for the different generators, and it appears the wrong procedure may damage the VR or generator. What is the correct procedure for my Generator?
-- >2b. For the polarization procedure, I believe I am supposed to disconnect the "BAT" and the "FLD" wires from the VR, start the engine, then momentarily touch the wires together. Does this sound correct?

Thank you!!

 

[JMOR]

Howdy all. This is my first post, and I am trying to verify if I have the correct voltage regulator and the correct procedure for polarizing the generator on my tractor. The tractor is not charging.

I am helping my 91 year old friend get his old tractor up and running that's been sitting for a while... I am a reasonably good mechanic, and this forum has been a tremendous help -- THANK YOU!

The tractor is a 6v (+) ground 1955(?) gasoline Ford 700 series. After a new set of points, going through the carb, (and a whole slew of other things that are important to do before a fist starting an engine that has been sitting,) it's now running well, but not charging. Battery is good. I went through the wiring with a voltage meter and it all seems to be good and connected correctly. The ammeter tests good.

The Voltage Regulator tests bad; inside the VR one of the hair-thin coil wires is melted with an open circuit.

The generator has 2-brushes, and is the "externally sourced, internally grounded field" version, with endcap number OHA-10125-A. I have bench tested it as well as I can without a growler, and it now tests good. There was missing insulation from the internal Field wire near the points, which may have been shorting to ground. I fixed that and now want to repolarize the generator.

I bought what appears to be a correct replacement VR, but it appears to be slightly different from the one it is replacing.

Here are my questions:
1. Does the "externally sourced, internally grounded field" generator require its own unique voltage regulator, or does it share a VR with the "internally sourced, externally grounded field" generators? They both look about the same, but the terminals are not all in the same order.
2a. I see there are different generator polarization procedures for the different generators, and it appears the wrong procedure may damage the VR or generator. What is the correct procedure for my Generator?
-- >2b. For the polarization procedure, I believe I am supposed to disconnect the "BAT" and the "FLD" wires from the VR, start the engine, then momentarily touch the wires together. Does this sound correct?

Thank you!!

The two types of VRs are definitely different! You need type-B. Generally, but maybe not forever & always, Type-A terminals are BAF and type-B are AFB Polarizing procedure you outlined is fine EXCEPT, should be done NOT running.

 

[Philosopher]

The two types of VRs are definitely different! You need type-B. Generally, but maybe not forever & always, Type-A terminals are BAF and type-B are AFB Polarizing procedure you outlined is fine EXCEPT, should be done NOT running.

That is incredibly helpful. Thank you!

 

[Jeff Hamilton]

Philosopher - I also found one of the thin wires burnt thru on my VR (Ford 860 6V, pos ground). I can't be sure, but I know the battery was in backwards when I got it - so that's what I blamed it on. I bought a new VR (this site) and found it to be overcharging. It overcharged until it burnt up. I got a Standard Blue Streak and have had no problems since.