FARMALL SUPER C

QUESTION I had the 3 brush generator rebuilt, a new u.s.a. voltage regulator installed and checked both wires on each side of the ammeter for breaks. one goes to the bat. terminal on vr the other to the neg. battery wire at the starter. when running the multimeter indicates 7.4 volts of charge at the battery. I tried 3 different ammeters but none will show charging. why won't the ammeter show charge?

This post was edited by ansavist on 06/11/2022 at 07:14 am.

What voltage measures at either terminal of the ammeter.

did not check that but have put it back together and that is a pain

I'm not sure where exactly the battery
cable goes to on a super C. But from what
you said (the lug on the starter), I
presume it goes to the starter. A starter
switch has got to be involved someplace.
Perhaps right there at the starter. If so,
make sure the wire from ammeter hooks up to
the battery side of that switch, not the
starter side.

MY H is battery cabled to a starter switch
mounted on the steering post, and a
secondary cable runs from that switch to
the starter.
Whatever you do, the ammeter wire that is
NOT going to the VR, has got to be hooked
up direct to the battery continuously. Not
a cable that is only activated when starter
switch is engaged. Thats what sounds like
is going on to me. Your getting it hooked
up to the starter cable, but not the
battery side of things. Wherever the
starter switch is, you got to be hooked up
to the battery side of that (not the
starter side).

Different manufacturers use different stamped in letters on the terminals. I have provided most alternatives in this answer.
The description you have supplied is incorrect wiring. The VR should be connected as follows. (assumes that this is a true VR, and not a Cutout Relay) Super C
Farmalls should have a 3 position light switch O-D-B = Off Dim Bright. A VR of that style should have 3 or 4 terminals, and be grounded at its mount base. A 3 terminal
is used on 3 brush generators. The terminals are B (Battery, connected to the amp gauge) A/Arm or GEN, Connected to the Armature terminal on the gen, and F connected
to the Field terminal on the Gen. A different regulator with 4 terminals (for later production and confusing) has 4 terminals, they are L, B(or BAT), A(or ARM, or
GEN), and F (Field).

The cutout relay, which is incorrect, only has 3 terminals, A (or ARM, or GEN), B(or BAT), And F Field.

on a 4 terminal Regulator, the The L terminal attaches to the Light Switch.

on a 3 terminal the F terminal is connected to the Field terminal on the gen. The A/ARM/GEN terminal attaches to the A terminal on the gen. The BAT terminal attaches
to the Amp Meter.

All of them have the B terminal attached to the amp meter on the terminal opposite the one going to the starter switch. all of them have the ARM or Gen terminal
attached to the GEN A terminal All of them (except the cutout relay) have the F terminal connected to Fielf on the Gen.

Jim

This info is also important. The supply terminal on the meter must be hooked to the battery negative post by connecting it to the starter switch where the battery cable attaches. Jim

the ammeter wire is fastened to the battery cable and is on top of the starter button so it is hot all the time there is fire all the time at the vr battery terminal even with the ign. switch off

Maybe I'm wrong again, but I thought all 3 brush generators need to be hooked to a cutout only.

thanks it is hooked to the neg battery at the switch

i misspoke the one ammeter wire is going to the bat terminal on the vr sorry if the battery is fully charged then would it be correct for the amp guage to not register any charge or shoiuld it show some charge? thanks

A properly operating VR will taper the charge to at or near zero with a fully charged battery. The at rest (not running) battery voltage should be 6.3 to 6.35, maybe
6.4. Charging measured at 3/4 throttle and across the battery terminals, it should be 7 to 7.2 volts, maybe as high as 7.4. If high, watch the battery for heat, and
using water excessively. Jim

thanks for the info that is what what i have it is not my tractor i am just working on it but the neighber insists that the amp guage should show charge all the time like his farmall h does

Could be wired wrong, one terminal is connected directly to the battery source.
Everything else goes to the other terminal.

Also the meter needs to be in range of the generator output, which is probably
10-12 amps. Most modern amp gauges are designed for alternator output, way
higher than a generator. You won't see much movement if that is the case.

When IH went to regulators they stayed with the three brush generator way up into the 4 & 350's.
The replacement generator in later years was a two brush option for 4 & 350 etc if you ordered new
one. Rebuilt ones were still three brush for a long time.

Not sure of the year they changed to regulators instead of high low charge with cutout but I know
later ones like my 52 H has regulator and three brush.

Can't remember If my 50 M had regulator or not as I switched it to alternator years ago.