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The amp meter on my 32 901 shows no charge when running. Shows discharge when I pull on headlight switch so it appears amp meter is working. Cleaned contacts on the voltage regulator, no change. This is a 3 wire regulator two coming from the generator and one going to the amp meter. Checked voltage across battery which shows 6.24 volts no change when engine is running. Engine starts as normal so appears to be no issues with general wiring and no blown fuses. So, could it still be the voltage regulator ? or is a generator rebuild in order ?

Do you have the details on the modifications to your charging system? Based on your description it apparently has been significantly modified and it can be difficult to diagnose problems with systems with unknown mods. The OEM system would not have a regulator but instead have a third brush generator and a simple cutout with but a single wire connection; adjustment of the 3rd brush would have established the charging rate. Your mention of having a full 3-wire regulator suggests your system has been modified and probably the generator converted from 3 to 2 brush configuration.

If that's the case and thats just my own guess, then you could very momentarily ground the field terminal of the regulator. If your ammeter now shows a large charge, your generator is OK and the fault is the regulator.

Believe there may also be a field fuse inside the later regulators as additional protection in case of a too high output current. Is that fuse still good?

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I had a very similar situation with my 31 last summer. The engine would start just fine, but I'd register zero amps at the meter when running. If I'd turn the lights on then there'd be a slight discharge. My solution was to have the generator rebuilt by a local shop and I sent the regulator/cut-out to KM Lifestyle for rebuilding. The field coils in the generator needed to be rewound, and there was some problem with the regulator. Now everything works great and I show a positive charge. PS. I have the original Owen Dyneto regulator on the generator too. Two wires come off the generator to connect to the cut-out and the regulator.

I have a fire wall mounted voltage regulator. I think the left wire is the generator and the center wire is the field wire ? I get a very slight movement of the amp meter needle to positive when I jumper between the gen wire and the negative pole on the battery. The wire coming from the amp meter attaches to the negative pole of the battery so I assume that is the charge side of the circuit ? Voltage is 6.24 and raises slightly to 6.47 when I rev the engine but no more. The amp meter needle used to go up more before this all started. I see no fuses in the wire from the amp meter to the negative side of the battery. Dave mentioned a fuse on the voltage regulator, but I do not see one ? is it possibly in the back and I need to remove the regulator to see it ?

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That was Howard that mentioned the fuse.

The original Dyneto-brand generator-mounted cutout and primitive control unit was fused but your charging system has been converted to a full generator control system which generally would date to post 1937 and that's the system you should be diagnosing.

What were the results when doing the test I suggested? Is the cutout solenoid closing as you increase engine speed?

Dave: I went back and cleaned all connections again all the way to the amp meter. Voltage at the battery ( new 2 months ago ) was 6.38. Jumper installed between the field terminal on the voltage regulator and the negative side of the battery showed running idle was 6.42, high idle 6.70 so not much increase.
What should I be seeing ? Amp meter needle moves to the plus side at high idle or higher but not as far as it did before this issue started. Could this be an early sign the gen is about to fail ?

Negative side of the battery??? Is your battery accidently installed backwards or did someone change your polarity? Your car was originally positive ground. You were to GROUND the field which would be the positive battery terminal unless your polarity has been reversed. Repeat the test but momentarily touch a wire between the field terminal and the frame or engine block, increase engine speed and note charging rate (or not).

Were you aware of your non-stock adaptations to the charging system?

Update, removed the generator and found shaft very loose, suspect bushings are completely gone. Have local guy looking at it now to see if it can be saved.