charging system

[gerritt]

I just bought a 1945 Farmall H and its not charging.Any suggestions...generator,voltage regulator? How can I tell if its a + or - ground system ? Could the previous owner have it hooked up wrong and have something burnt out? Its currently hooked up negitive. What has to be replaced to go to a 12v altinator besides the coil and bulbs?

 

[John T]

A lot of good questions, I will try to take them in order:

QUESTION:

I just bought a 1945 Farmall H and its not charging. Any suggestions...generator,voltage regulator?

ANSWER: 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.


QUESTION:

How can I tell if its a + or - ground system ?

ANSWER: Most 6 volt were originally Positive ground. You can tell what it is now by observing which battery terminal, + or - , goes to frame

QUESTION:

Could the previous owner have it hooked up wrong and have something burnt out? Its currently hooked up negitive.


ANSWER: YES That could have happened very easily. If one changes Polarity and doesnt re polarize the generator the Voltage Regulator could have been damaged (see above test to see if non charging is a VR versus the Genny problem).

QUESTION: What has to be replaced to go to a 12v altinator besides the coil and bulbs?

ANSWER: To go from 6 to 12 volts you,,,,,,,, 1) Need to EITHER add a voltage dropping (12 to 6) external series Ballast Resistor after the ignition switch and ahead of/before the coil ORRRRRRRRR get a new full true 12 volt coil NO BALLAST REQUIRED,,,,,,,,, 2) yes change light bulbs,,,,,,,,,,3) Most all alternators use negative ground remember,,,,,,,,,, 4) The coil needs to be wired to match your polarity, i.e. for neg ground thats the lil + getting voltage from ballast or switch while the lil - wires to distributor


For my complete non charging troubleshooting procedure, click the URL link below, I hope this answered all your questions.

John T
John Ts Troubleshooting Procedure

 

[gerritt]

Very helpful , thank you. Does anyone make an electronic regulator without points etc.?

 

[John T]

Your Welcome, I dont know the answer as far as anyone who makes a suitable replacement "electronic" Voltage Regulator for these old DC Generator tractors although several make the simple 2 terminal solid state/diode cutout relays.

John T