50 JD B Charging System - Not Charging

Have a 50 JD B which is not charging the battery. With the tractor running, I get essentially no voltage reading between ground and the armature post on the generator. Not quite sure where to go from there and don't want to blindly throw a new generator at it.

One first thing to try is when running use a jumper to ground the Gennys FLD post to see if it charges then ????

If so but NOT otherwise, the VR is bad, or the VR isn't grounded, or wires open from FLD on VR down to gennys FLD post. Insure a good ground on BOTH the Genny and VR and see if it charges.

When running and gennys FLD post grounded see if it shows charge if you momentarily jump BAT over to GEN/ARM on the VR ?? If so but not otherwise the VR's Cutout Relay may not be closing as it should and again insure BOTH genny and VR are well grounded.

When running if the gennys FLD is grounded and BAT is jumped over to GEN/ARM the VR is basically out of the equation so if no charge then the Genny may be bad.

To be safe Polarize the Gennys BEFORE starting and trying the above...??.

The Motor Test described in my procedure below is another way to test a genny independent of the VR, check it out

The belt needs to be tight, all the wiring including ammeter correct and intact and VR and Genny grounded

For a complete detailed step by step procedure to find the cause of non charging CLIK ON MY TROUBLESHOOTING LINK BELOW

The genny may just need new brushes or the brush hold down springys are stuck/corroded or the commutator is all gunked up, look at those easy cheap simple things FIRST and try my procedure above. OF COURSE THE GENNY MAY JUST BE SHOT

John T
John Ts Troubleshooting