will not charge 2 bad VRs?

Ok since there is all this talk about charging rates and bad vr's I may see if you can help me.
I have tried 2 VR's that I thought were good and one new one and it doesn't work. I ground the Feild terminal on the VR to ground on the tractor and I get 10volts on the gage. Nothing I do works. I have polarized it also.
Do I have 3 bad VRs or do I have another problem?
I have even took a jumper from the ground wire on the vr to ground on the tractor. I pull the ignition switch out it shows discharge. This is on a 1955 Farmall 100.
any suggestions?
I am going to put a VR on my 1945 A if I wire this right It will totaly by-pass the charging LHDB switch?
Is there anyway to bench test the VR?
How do you tell if you have a 3 brush genny or 2 brush? will the early 1948's and before have 2 or 3 brush? My dad has a 8volt on his 48 H can I adjust it to charge that battery?
Thanks
Chad

The Ignition switch must be in the off position when you polarize the system. I found that out by accident. I have since learned that it is the correct way to do it. ????????????
SDE

thanks I have done it that way.
usualy if it works it charges the right way. When I have had problems it showed a negative charge untill I polarized it.
I went back out there and tried my 100 and my farmall A that is hooked up with a VR. Niether one of them work unless I have the Feild hooked directly to ground and then they show about 12-15 volts with throtal all the way up.

What voltage are you working towards? If 12volt, and a 12volt generator, and the battery is charged (very important), then if the grounding of the field only makes 10 volts or so, the generator is not doing its job. No regulator will make it work.
On the older machine (assumes 6v) the grounding of the field will make 8vlots or so at the battery. A three brush generator has three brushes located in the non pulley end (little carbon rectangles pressed against the segmented commutator. A 2 brush has 2 brushes!
Do not use the wire coming from the light switch for the regulator at all. it is only used with a cutout relay based system. They can look the same (VR and Cutout) JimN

If you dead ground the gennys FLD post and if you by pass jump around the cutout relay by momentarily jumping the VR's BAT to its ARM/GEN terminal yet she still fails to charge,, THE VR ISNT THE PROBLEM CUZ ITS OUT OF THE EQUATION

THEREFORE if theres no charge its either a bad genny or else shes not wired right or the genny isnt grounded.

You need to work through my Troubleshooting Procedure posted below, in it the MOTOR TEST can test the genny independant from any VR etc

YES if you use a VR the LHBD doesnt control charging anymore, the gennys FLD post is no longer wired to the LHBD switch, but to the FLD post on the VR

If you convert a 3 brush genny from cutout relay and LHBD light switch over to a VR Id adjust the third brush for max charge

Its easy to look see if theres 2 or 3 brushes, the older gennsy were 3 brush n used the LHBD n cutout relay system versus the later 2 brush that used a VR

If its a cutout relay system many 6 volt gennys will still charge an 8 volt battery NO CHANGES REQUIRED other then if its a 3 brush Id set it for max charge

If its a VR that has a Current control relay only it can still charge an 8 volt battery

If its a VR that has a Voltage control relay or a combo current n voltage control relay, it should be adjusted to charge an 8 volt battery

http://www.ytmag.com/cgi-bin/viewit.cgi?bd=jd&th=

John T
John Ts Troubleshooting Procedure