farmall 130 charging trouble

I have a farmall 130 that isn't charging. I went through the John T trouble shooting guide and still can't pin point the problem. When I do the motor test and remove the field terminal ground it speeds up but not very much. Nothing I have done gets more than 6 volts at the battery and the ammeter never goes to the charge side. It is a 6 volt negative ground system. Any help is greatly appreciated.

6 volt should be + ground. Try changing the cables then polarize the generator before starting it.

switched the battery connections and repolarized but still not charging. Did the motor test and still the same thing. How do i measure if the generator is putting out? All my connections seem good but I am stumped.

There is a possibility that the gen is not
connected to the battery. This would cause the
gen to teat good but not charge.
With it running, and all wires connected as
originally wired, run a wire from the battery to
the gen Armature post. (not field)
if it sparks, that indicates the gen is capable of
putting out voltage do not leave it on there. If
no spark, make sure the gen is grounded at the
frame to bracket to engine. If it is for sure
grounded try it again. If no spark, Ground the
field terminal (leave things all connected as
before) if still no spark, the gen is suspect.
If it sparks when first tested (nothing but the
first temporary jumper) then I suspect the amp
gauge is open (defective) or the regulator's
cutout relay is not closing. To check this use a
solid copper wire to jump from the Gen terminal on
the regulator to the Bat terminal on the
regulator. If it now sparks and shows charge, the
VR is not closing. (Repair is pretty intense, but
best done if experienced.) replace the Regulator.
If still no spark at the jump and no charge it
further condems the amp meter. (you are sure all
connections are shiny and tight!!!) Jim

just ran all those tests. sparked when it should, double checked all connections and they looked good. found another diagnostic post from sadfarmall and I think I have a bad field coil. most I ever got from the gen was 2 volts. I don't know anything about motors and generators so I think I'll turn it over to an expert at this point. Thanks for all the help. At least I learned a little more about the electrical system.