Ferguson TO-20 rewire and generator done!

I just finished getting my Ferguson TO-20 rewired. And I just have to pick up this afternoon my generator and voltage regulator from the
repair shop. Had a question though my mechanic said something about its only a 13 amp generator and kind of a small generator. Also he said
my brand new voltage regulator I just bought only about 3 months ago was shot? I don't understand how it could be shot? I did play around
with polarizing the voltage regulator but don't really now what caused it to go? He gave me a new one, but also he fixed my generator and
said the adjusting plate the little screw screws into fell into the bottom of it to hold the 3rd adjusting brush. He said at idle it only
puts out about 5.2 volts is that right at idle or no? Thanks any help is appreciated!

My 35 diesel only puts out 13 amps but it is 12v. Generators not charging at idle is normal.

My understanding of a 3rd brush generator is there is no regulator, just a cut out relay.

The voltage is adjusted by moving the 3rd brush. The cutout relay is only there to stop feed back through the generator when it is not producing voltage.

I didn't think TO20 ever used a 3rd brush generator, but maybe they did way back in the older ones.

Don't expect much of anything from a generator at idle, especially if it has a big pulley.

Might not be relevant, but I recently discovered that the new 12v regulator I bought for my converted TEA20 did not regulate properly. The voltage was set much too high, which boiled all the electrolyte out of the battery. A shop might have said it was "shot", even though it probably had less than 30 hours of operation on it. Actually servicing these things appears to be a dying art, mechanics just want to replace things.

DC Generators aren't very efficient, so they make a lot of heat for the current they produce. Automotive generators have vents and fans to pull air through the housing to keep them cool. but a typical tractor generator is sealed, so heat only escapes through the housing. So they have to be limited to much lower current output than the same physical size generator in automotive service.

5.3v at idle is normal for a 6v generator. The cutout will open and you may or may not see a dim glow in the warning lamp.

Service manual says the TO-20 and TO-30 use a Delco 3-brush generator, with a regulator. The third brush is supposed to be adjusted to limit the maximum output current, but the regulator also senses current (as well as voltage).

I went through 3 voltage regulators over a period of about 2 years on my Ford NAA. The last one was an Echlin from NAPA. It lasted about 6 months. Yes the generator was good, rebuilt and passed the full field test. They just don't make them like they used to. I gave up and converted to a 12 volt single wire alternator. Works good.

FWIW, I know of a fellow that makes solid state regulator circuits to go inside original housings, for the antique car market. He could probably be talked into doing a 6v tractor version, if there was enough demand for it.

But there is not a whole lot inside these regulators, so opening them up and repairing them is definitely possible. I've repaired the unit for my 56 Triumph car several times (which is very similar, although for 12v instead of 6v).

The Lucas box used on the Triumph appears to have a particular design weakness inside, in that two of the electrical joints are not soldered or crimped, but rely on contact between a brass sleeve and the steel post that goes through it. Adding a jumper across that joint brought several of them back to life.

I've not had a Delco box apart (yet), but any problem has to be either dirty contacts, or a bad connection, or misadjustment. There just isn't much else to go wrong!