John T....Question

Does a VR need to be polarized every time the battery is removed from the tractor?

I have seen you say before don"t jumper to the Field terminal from the VR....what does that do?

If a VR is not polarized after a battery disconnect, what does that do to the VR?

Thank you for your expertise in this matter. Your knowledge on this topic has helped me greatly in the past.

Kris A NC (now IN)

"Does a VR need to be polarized every time the battery is removed from the tractor?"


NO, a VR doesnt need Polarized, its the Generator that requires polarized so it begins to charge at the polarity matching how your battery is configured lest you damage the VR

NO, genny doesn't need re polarized if the battery is removed (assuming battery is re installed at same polarity), when the tractor is shut down the VR's Cutout Relay opens and its basically removed from the battery anyway.

HOWEVER it don't hurt if you wish to polarize. Its only if a genny sits a long time never used its soft iron field poles may eventually loose their residual magnetism whereby polarization is required.


"I have seen you say before don"t jumper to the Field terminal from the VR....what does that do?"

It may not do serious harm but current flow would be in the opposite direction as that required to correctly Polarize the Generator and if the VR is still in the circuit, its circuitry may draw excess current and current could flow to ground via the VR versus it flowing through the field windings (but even so its in wrong direction).

"If a VR is not polarized after a battery disconnect, what does that do to the VR?"

Actually, if the GENERATOR isn't polarized to match battery polarity, it can damage the VR.

NOTE its quite possible a genny shop may polarize a genny for Neg Ground so if your tractor is Pos ground be sure to polarize it BEFORE start up

Got it??? PS I cant do a good job in a few sentences here compared to when I used to give an hour long seminar workshop on charging systems so this isnt perfect or complete, just short n sweet AND NO WARRANTY.

John T

I'm not John T but polarization is applied to the generator, not the VR, so you are not polarizing the VR.

Good practice would be to polarize the generator each time some electrical work is done just to be sure. It doesn't hurt anything to polarize even when it's not needed. I follow this guideline.

John can shoot my reply full of holes if it needs that, LOL, John

"Holes" are in transistors IIRC, right John??

Thank you John T for the information and the clarification. I was just looking for simple answers. I have learned a lot from your writings on the subject, but just had those few questions....I had my battery removed for a day and forgot to polarize when reinstalled. I wanted to make sure I didn't just burn up a new VR. Thank you for sharing your knowledge.

Kris A NC (now IN)

""Holes" are in transistors IIRC, right John?? "

Tell ya what, wayyyyyyyy back in the late sixties at Purdue I still took a course in vacuum tubes and the hardest course I took was "Electronics of Solids" aka Solid State Physics which had to do with Maxwells Equations and holes and molecular structure and quantum mechanics YUKKKKKKKKKKK. I sort of recall electrons (Neg charged particle) flowed in one direction and the spaces left behind (the Holes) flowed in the opposite direction.

I guess "HOLES" are wherever electrons have been displaced?? Its the PN Junction where all the hard core physics takes place and I don't remember beans more then that lol Bob and Soundguy and JMOR etc are MUCH better equipped at this them myself, Im too dern old and outdated lol DC Circuits 101 and AC Power Distribution are more my thing.........

John T