MF35 charging problem

[Massey35]

I need some help with a charging problem on my 62 MF35 3cly diesel. It has a new VR (Delco 1118981) , new battery(neg ground) and wiring harness. I've had the genny (Delco 1100383) checked and it is good. The tractor starts strong and all gauges are working properly. The ammeter goes to - when the lights are turned on (tractor not running) and also goes to about 10-15 amps neg when the tractor starts and goes back to 0 and stays there at any rpm. I would say this is normal given that the battery is new but once the lights are turned on the ammeter goes to the - side and stays there no matter how much the rpms are increased.

Troubleshooting the electrical system isn't my expertise and I guess I try too hard to find the answer and confuse myself. I've read about polarizing and get confused about what I've read or been told. One place will say flash jumper the gen and the bat terminals on the VR with the tractor running. Then I will read about flash jumpering the field on the genny to the bat terminal. I've read today that there is a difference in gennys (A and B circuit) I can't find what type I have. Any help anyone can give me to get my charging system working I would appreciate. I've taken reading across the battery terminals with the tractor running at various rpm but see no changes. I can't say for sure that the gen is charging. What am I missing?

 

[Soundguy]

you never try to polerize a genny when running especially if you don't know what circuit type.. if you do it wrong, for instance.. polerize an a circuit like B circuit while running, you will let all the magic smoke out of the 40$ regulator.

I'm not up on masseys.. I'm a ford guy.. and I'm up on gennies.. here are a few things you can do.

1, take the vreg and flip it over.. there will usually be 1 or 2 bias resistors on the bottom connecting between tabs and terminals on the underside of the vreg.

if you see a resistor between field tab and ground and none other.. then it is A circuit

if you see a resistor between armature and field, it is B circuit. ( other resistors may be present ).

once you know the field type of the reg, if it is an oem replacement reg, and the genny is an oem style, you know the field type of the genny.

here's a good first test.. a motor test.

slip belt off the genny.

jumper battery hot to the armature stud on the genny.

now, if you determined it was A circuit, then jump the field stud on the genny to ground... the genny should spin.. if it does.. that's good.. most gennies that motor, will charge.. most gennies that charge, will motor.

If instead you determined it was B circuit, then jumper bat hot to Armature AND field tabs on the genny.. and it should spin.

now.. if you determined it was a specific circuit type and it won't spin, for the heck of it, try to motor test it as the other circuit type. if it works, you have a genny that is a different circuit type than the regulator.. and this won't work.

next test.. full field.

put belt back on genny. motor test has told you what circuit type it is, and examination has told you what regulator you have. if they match up, lets do this.

start tractor.. get to 2/3 rpm.. if no charge on ammeter, and no charge at battery as tested with a volt meter ( 7.2 for 6v system, or 14 or so on a 12v system ).. now disconnect field wire from genny and fold back. take a short jumper wire and jump field on genny to ground if A circuit.. or to bat if B circuit.. look at amp and volt meters again. if it shows a charge, then the field portion of your vreg is bad.

if still no charge, jump between arm and bat on the reg, then re jump the field on the genny to appropriate spot depending on field type. In this situation, you really should see a charge on the meters IF your genny past a motor test, as you have completely bypased the reg, and are making the genny charge at full potential with no cutout in line. if this fails to show charge.. i think you need to check your ammeter wireing.. and or the armature / battery line to/from the vreg for an 'open' fault.

soundguy