Tim Crawford
New User
I have a 1954 Ford NAA, bought it two years ago.
The amp meter on the tractor has never indicated
that there was any current flow from the generator
into the battery. When you turn the key on the
amp meter reads about +4 amps,this is the opposite
of what I would expect but it does give a reading.
Then as I try to start it the ampere meter does
move as the motor is being rolled over, again this
is what I would expect. Once the tractor starts
the ampere meter goes back to +1 amp and does not
move, it sits at +1 amps when the tractor is shut
off too. My thought was that the generator was
bad or the voltage regulator is defective, but I
have been able to determine that the generator is
producing a charge. I have looked at the brushes,
there is very little wear. So that being said I
decided to buy a voltage regulator the one on the
tractor looks to be pretty old. I bought a
voltage regulator that would fit a 6-volt Ford NAA
B circuit, it said it would also work 600, 700,
800, 900. I took the old one off and it had a
rattle, I opened it up and one of the screws had
fallen out of one of the plates. I decided to
put the new one in since I had already bought it.
I got the new one in and verified that the wires
were hooked up correctly, ground was to the ground
wire on the generator, the BAT was hooked into the
terminal block, the FLD was connected to the field
post on the generator, and the ARM was connected
to the armature post on the generator. I then
turned the key on and the ampere meter indicated
+4 amps just like it did with the old voltage
regulator. I then started the tractor. The
ampere meter went back to +1 as it usually did and
stayed there for about 5 seconds, then the needle
jumped to -30 amps and stayed there for 15-20
seconds. The generator started to make some
strange noises, and then the amp meter needle
started to jump from -30 to -20, back to -30, down
to -10, up to -30 it was all over the place and it
would stay mostly at -30 amps but it stayed at
other settings for 15-30 seconds at a time. I put
a multimeter on the battery as the tractor was
running and it indicated that the battery was
getting 18-22 volt charge. I shut the tractor off
and checked the generator and it was very hot. So
I guessed I fried the voltage regulator some how.
I went and bought another voltage regulator and
very carefully installed it and verified the
wiring was correct. I started the tractor and the
very same thing happened! What is happening here?
Do I have the wrong voltage regulator? Could it
be bad wiring, a short in one of the wires? The
wires are wrapped together in a harness so I can
only see the ends and the ones connecting to the
generator have a number of cracks in them. Are
the my new voltage regulators reparable? I opened
the one up and there was no sign of any damage,
like melted wires everything looks fine. Could I
have a mismatch with the generator and the voltage
regulator, could I have an A-Circuit generator?
The previous owner may have put an A-Circuit
generator on the tractor not knowing? Is there a
simple way I can tell what type of generator I
have? There are a lot of questions here I hope
someone can give me some advice on what to do
next. Thanks.
The amp meter on the tractor has never indicated
that there was any current flow from the generator
into the battery. When you turn the key on the
amp meter reads about +4 amps,this is the opposite
of what I would expect but it does give a reading.
Then as I try to start it the ampere meter does
move as the motor is being rolled over, again this
is what I would expect. Once the tractor starts
the ampere meter goes back to +1 amp and does not
move, it sits at +1 amps when the tractor is shut
off too. My thought was that the generator was
bad or the voltage regulator is defective, but I
have been able to determine that the generator is
producing a charge. I have looked at the brushes,
there is very little wear. So that being said I
decided to buy a voltage regulator the one on the
tractor looks to be pretty old. I bought a
voltage regulator that would fit a 6-volt Ford NAA
B circuit, it said it would also work 600, 700,
800, 900. I took the old one off and it had a
rattle, I opened it up and one of the screws had
fallen out of one of the plates. I decided to
put the new one in since I had already bought it.
I got the new one in and verified that the wires
were hooked up correctly, ground was to the ground
wire on the generator, the BAT was hooked into the
terminal block, the FLD was connected to the field
post on the generator, and the ARM was connected
to the armature post on the generator. I then
turned the key on and the ampere meter indicated
+4 amps just like it did with the old voltage
regulator. I then started the tractor. The
ampere meter went back to +1 as it usually did and
stayed there for about 5 seconds, then the needle
jumped to -30 amps and stayed there for 15-20
seconds. The generator started to make some
strange noises, and then the amp meter needle
started to jump from -30 to -20, back to -30, down
to -10, up to -30 it was all over the place and it
would stay mostly at -30 amps but it stayed at
other settings for 15-30 seconds at a time. I put
a multimeter on the battery as the tractor was
running and it indicated that the battery was
getting 18-22 volt charge. I shut the tractor off
and checked the generator and it was very hot. So
I guessed I fried the voltage regulator some how.
I went and bought another voltage regulator and
very carefully installed it and verified the
wiring was correct. I started the tractor and the
very same thing happened! What is happening here?
Do I have the wrong voltage regulator? Could it
be bad wiring, a short in one of the wires? The
wires are wrapped together in a harness so I can
only see the ends and the ones connecting to the
generator have a number of cracks in them. Are
the my new voltage regulators reparable? I opened
the one up and there was no sign of any damage,
like melted wires everything looks fine. Could I
have a mismatch with the generator and the voltage
regulator, could I have an A-Circuit generator?
The previous owner may have put an A-Circuit
generator on the tractor not knowing? Is there a
simple way I can tell what type of generator I
have? There are a lot of questions here I hope
someone can give me some advice on what to do
next. Thanks.