1946 Generator Blues

[rmmccon]

I have a 1946 Chief with the high output generator and regulator and my system does not charge the battery. All wires and brushes are good. The first thing I diagnosed was that the generator case did not have a good ground path to the frame because the frame of my bike had been repainted. So I sanded off some paint underneath the generator mounting bracket and got a good ground path. The ground path I checked was from the armature and field wires (brushes) to the frame and engine. I also adjusted the 3rd brush for maximum charge rate (it was initially set for the minimum charge rate). I adjusted the 3rd brush to be about one commutator bar from the main brush. The next test I did was the “motoring” test. I grounded the “field” wire to the case (ground) and applied 6 volts to the “armature” wire coming off of the main positive brush. This test was successful as the generator “motored”. If not previously done, “motoring” should have also properly polarized the generator for service.

I thought perhaps that the bad ground connection and that properly polarizing the generator was all that was needed. But when I put the generator back together and made all the connections and started the bike up it still doesn’t charge according to the ammeter.

I want to keep the system original (no matter how bad a generator system is) so I am not interested in converting over to a 12V system.
What else could be wrong? A bad regulator? My regulator looks like a reproduction (most likely from Greer).

Any advice would be greatly appreciated.

[cdf6333]

Have you used a voltmeter on it? Measure battery voltage, engine off. Should be between 6.1 and 6.5 volts. Then fire it up and it should easily go to 7. If a generator motors it will produce electricity. Regulators are a problem too, especially the small fuse.
IF you can find a cutout, put the field wire under a screw to ground and use the cutout for a test.
2nd, are you sure that the battery is OK?
Bob

[gharper]

Sounds like you've covered first base at least, in that motoring the generator would indicate it will charge, at least some. Are you 100 % sure the wires coming out of the generator are connected correctly? The wire from the + brush should go to the A terminal of the regulator, the field - wire to the F terminal. The next item to eliminate is the "regulator" itself, as it is eroneously called. With everything connected and the cover removed, start the engine. Attach a volt meter to the battery. It should be reading around 6.5 volts. There are 2 relays under the regulator cover, locate the one with the heavy wires wound around the coil. Simply push down on the top lever of that relay, closing the points. This should connect the generator to the battery and battery voltage should climb up quickly to 7-8 volts, may need to rev the engine slightly. If the voltage goes up, there is a problem with the regulator. If not, try bypassing the regulator completely by grounding the field wire and connecting the + brush wire direct to the battery while the engine is running. Again, battery voltage should jump right up. If it does, again the regulator is the culprit.

My belief is that if you plan to ride much, convert the generator to 2 brush and get a true voltage regulator. This will eliminate the 3rd brush and mechanical cutout as well as the 2 stage charging system. It will save you lots of trouble down the road! Check out my web site: www.splitdorfreg.com and click on the Autolite tab. You will find info on the Autolite TC look alike regulator that I make


Good luck!

Gene Harper

[rmmccon]

The battery voltage with the motor not running is around 6.3 volts. With the motor running the voltage is the same or less. I also tested the battery with a hydrometer and the battery is in good condition.

From what I can see (and using an ohm meter) is that the wire from the 3rd (adjustable) brush goes to the “Field” coil which has smaller gage wire winding next to the external resistor. The brush to the right of the adjustable brush (looking from the commutator end) goes to the “Armature” connection of the regulator (large gage wire winding). The bottom side of the regulator has connections labeled “F” and “A”.

I’ll try the relay test you mentioned this weekend.

Thanks!

-Mark

[phillie]

I just send mine to Indian Frank. He knows whats what.