Problems with 1945 Farmall A charging system

[Jerry Stevens]

I just bought a 45 Farmall A and the previous owner put a 12 volt battery on it but didn't convert it. I put a 6 volt back on it but it still shows it discharging on the ammeter. Did the 12 volt knock out the voltage regulator and generator? Any advice?

 

[Jerry Stevens]

Surely one of you out there can provide some advice. I hate to buy a VR if it's not needed. I'll try and get a multimeter on the generator today. Help!

 

[Willl]

I'll try and get a multimeter on the generator today.

Your going to have to, either that just start throwing new parts on it till it fixes itself.

 

[Soundguy]

rarely does adding a 12v battery kill it.

in any case.

polarize the genny ( jump bat hot to armature ) and then see what she does.

use a volt meter.. remember .. an ammeter can read backwards if you have changed the ground polarity.

a good test is to see if the needle deflects negative with ign on, points closed.. or lamp on, both with tractor not running.

if metr shows negative deflection on those.. then it is liekly wired correct with respect to ground polarity.

now.. if o charge after polarization do this:

slip belt off machine.. jump bat to armature.. ground field.

genny should spin. if not it needs a trip to the DR

if it does spin.. then it should charge. most gens that motor, will charge. most gens that charge.. will motor.

next.. assuming it motored..

slip belt back on.. start up tractor.. nothing on meter?

jumper field to ground.. if she starts charging.. but dies again when you remove jumper.. ensure wire harness from vrg to genny is intact. if it is.. vreg field circuit is bad... repalce vreg.

if still no charge.. then jumper bat to arm as well as leaving field jumped to ground.

if this produces charge, then cutout relay is open and field may be open as well in vreg.. etc.

post back observations..

 

[Clint S]

It may be a coincidence, but on my Farmall 200 my 6v battery went down ( it was many years old) I put a 12v battery in it to start it. Ran it for a few weeks just starting with the 12v disconnecting the battery after starting and running it on the Genny. One day I left the battery hooked up and sure enough a bit later it stalled out. Took the genny and tested it and it tested fine the voltage reg was crapped out. I converted to 12v and could not be happier with my conversion.

 

[Jerry Stevens]

Good stuff Soundguy! Thanks. Clint, I probably will but would like to see why it's not charging. Things to do after work and the weekend! Thanks all.

 

[Soundguy]

post back.

if the gennies good.. you are most of the way there..

 

[Soundguy]

post back.

if the gennies good.. you are most of the way there..

 

[Jerry Stevens]

I checked the gen last night as you said and it motors. I believe it's the VR so have ordered a new one. More on this later. Thanks!

rarely does adding a 12v battery kill it.

in any case.

polarize the genny ( jump bat hot to armature ) and then see what she does.

use a volt meter.. remember .. an ammeter can read backwards if you have changed the ground polarity.

a good test is to see if the needle deflects negative with ign on, points closed.. or lamp on, both with tractor not running.

if metr shows negative deflection on those.. then it is liekly wired correct with respect to ground polarity.

now.. if o charge after polarization do this:

slip belt off machine.. jump bat to armature.. ground field.

genny should spin. if not it needs a trip to the DR

if it does spin.. then it should charge. most gens that motor, will charge. most gens that charge.. will motor.

next.. assuming it motored..

slip belt back on.. start up tractor.. nothing on meter?

jumper field to ground.. if she starts charging.. but dies again when you remove jumper.. ensure wire harness from vrg to genny is intact. if it is.. vreg field circuit is bad... repalce vreg.

if still no charge.. then jumper bat to arm as well as leaving field jumped to ground.

if this produces charge, then cutout relay is open and field may be open as well in vreg.. etc.

post back observations..

 

[Soundguy]

post back if you need help, and good luck