Gen vs VR, how do I know

I have checked all my wiring and am wired according to the drawing I saw on here. I have a 3 brush gen and a VR with 4 wires connected and grounded, but stil nothing. How do I know if it is the gen or VR?

by the way, it is on a 1941 Farmall H

This was has been covered in detail numerous times, check the archives and copy and save to a folder the ones you like.
The simplist way is to use a jumper wire and ground the gen field terminal and if it charges the gen is good.
Dell

ALL componets in the system need to have a good ground even the control sw andthen polarize the ben and like other post said ground the field this will tell you whether the gen is at fault or the reg.

TO DETERMINE IF ITS A GEN OR VR OR CUTOUT RELAY PROBLEM

5. a) VOLTAGE REGULATOR SYSTEM: With the tractor running, temporarily ground the Gens Field post to case. If she charges then but NOT otherwise, the VR may be bad, or a wires missing from VR's Field post to the Field terminal on the VR, or the VR isn’t well grounded.

b) IF IT’S A CUTOUT RELAY SYSTEM and she charges only if you dead ground the Field but NOT otherwise, its either a bad switch or the switch isn’t well grounded or else the wires bad or open from the Gens Field post up to the switch. INSURE THAT GOOD SWITCH GROUND AND WIRING

6. If she still don’t charge, leave the Field grounded and jump a wire across from the VR or Cutout Relays BAT terminal over to its GEN terminal (jump by passes the cutout relay) and see if she charges. If then but not otherwise, a VR's cutout relay isn’t working correct (maybe points burned/carboned) or a Cutout Relays NOT working or not wired correct.

7. With the 2 steps above, you have basically by passed the VR or Cutout relays functions, so if she still don’t charge, you're left with a bad battery or wiring or the Gen itself.

8. MOTOR TEST. You can Motor test the Gen. If its grounded and you remove the belt and apply hot battery voltage direct to its ARM Post and have the Field Post dead grounded to frame, it should motor n run well (Armature n Brushes and Commutator likely okay). Then, if you next remove the Fields ground and it speeds up some, the Fields probably good. If it passes both those tests, it should charge, and if not, it may be a wiring or battery or grounding problem. The hot battery voltage may be taken off the VR's BAT terminal or the starter post or the battery itself for this test.

Below is the entire Troubleshooting Procedure

John T
John Ts Troubleshooting

A 41 will have originally used a light switch based gen control. (Low charge, High charge, Dim, Bright) This must be completely out of the system to use a regulator. The F terminal on the gen must be directly connected to the Field terminal on the VR. The wires to the light switch must be abandoned. As John T points out, good grounds must be made at all parts, and the Gen must be polarized (Tractor off, all wires connected, jump for one second between Gen terminal of VR to Bat Terminal of VR making a nice spark) JimN