Good morning Rusty, good questions
1) "Question, If The genny and VR is good and I hook a Volt meter to BAT on VR and the other lead to GD with tractor running should I get a reading? YES and battery voltage not running but 13 to 14 or so if running at fast RPM if all is wired right and working ???????????????
YES Iffffffffffff the BAT terminal on the VR is wired to the ammeter (or even if BAT on VR somehow gets to hot battery post otherwise for that matter) and its continuous not open and its wired eventually to the battery ungrounded post, often via a wire to the starter/solenoid INPUT where the big battery cable attaches, or to battery itself? A volt meter on the BAT terminal on the VR should read hot battery voltage all the time (via its connections above) otherwise the genny cant get connected up with and deliver a charge.
If alls well and all connections above are in place at fast RPM a good genny and VR should raise battery voltage to at least 13 up to 14 volts subject to RPM and genny and battery.
YOU HAVE TO GET BATTERY VOLTAGE ON THE VR'S BAT TERMINAL or the gennys output cant charge the battery
Once you have polarized the genny and insure the VR has a good ground AND GET IT WIRED SO BAT ON VR IS HOT when running if you use a jumper to temporarily dead ground the gennys FLD post SHE SHOULD FULL CHARGE. If so but NOT otherwise, the VR is bad or not well grounded or is not wired correctly
NOTE it came original as POS Ground, how are you wired now ??????????
NOTE a volt meter on ground and the VR's GEN/ARM post would read the gennys output when shes running
CAUTION if a shop worked on the genny it may not be polarized at POS ground like your tractor was originally BE SURE TO POLARIZE THE GENNY BEFORE STARTING OR IF WRONG IT CAN DAMAGE THE VR
2) "Had Columbus auto electric check out genny and VR. Said genny was good but VR was bad. Put new VR on and installed on tractor. Made sure of good ground. Still not charging"
a) Hope you polarized the genny BEFORE starting or the VR may be damaged
b) See if it charges at fast RPM if you ground the gennys FLD post??????? If so but not otherwise as I said above the VR
is bad or not well grounded
SUMMARY you have to be wired right so BAT on VR is connected to battery,,,,,,,,,,Genny should be polarized to be safe,,,,,,,,,VR AND GENNY needs a good ground,,,,,,,,,VR needs to be compatible with your ground be it POS as original or NEG,,,,,,,,,,
Theres more but this is a start for now, post back any questions. Check out my in depth Troubleshooting Procedure linked below for more info
John T
John Ts Charging Troubleshooting