With the engine  running what voltage should I measure at the battery terminals? I know that a 12v alternator puts out about 13.4 but I've never had a 6v vehicle with a generator.  Thanks.

Are you idling the engine?   Generators won't charge at an idle like an alternator will.   I don't know the rpm they kick in,  but have someone run it at a fast idle and see what happens.   Check your ground to make sure its not corroded under the voltage regulator and that there is a good ground wire going from the engine to the body of the vehicle.   I usually ad a ground from the generator bracket directly to the frame also just to be sure.

6.8-7.2 Volts at fast Idle. At Idle U wont see much if any above 6 Volts.

  

I forgot that generators are lazy until revved up..  I  was planning on additional ground straps.  Engine to firewall and generator bracket to frame.  The 55 bird engine sits on rubber mounts, so grounds are essential.  Thanks.  I'm hoping to see about 8 volts.

Best thing you can use at those ground connections. I use it everywhere when I rewire or add something. Bare metal under it of course. There’s other brands, this one is typical.


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https://www.specialized.net/cp8-tb-thomas-betts-kopr-shield-compound-8-oz.html?gclid=EAIaIQobChMIzejju5v_2wIVF6vsCh26SAGLEAQYASABEgLxB_D_BwE

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

I don't think you will see 8 volts which is usually beyond the range of a 6 volt generator.  At eight volts, you may be popping light bulbs. Biggest thing with a 6 volt system is the grounds already mentioned plus the correct size cables.  Use heavier cables than a 12 volt car.


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

Generators can be modified to output 8volts usually due to old wiring and bad connections/grounds. My electric guy says its not recommended. 

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire