My 29 Hupp model M 8cyl has burned up the cutout and I want to trouble shoot the charging system before installing the new cutout. I was told there is a difference between testing the generator output "cold" vs "hot"? This is a three brush single wire Autolite generator #gag4106 and cutout #cb4012.What should I do to insure proper charging and proper output and cutout operation?

Here is the link you need to answer your charging questions:

http://www.fifthaveinternetgarage.com/

The generator would not burn out the cutout as it only pulls the contacts together by electromagnatizm. If the contacts have burned or pitted they may have just used up their anticipated life or were not adjusted properly. the output of your generator is constantly monitored by your ammeter you can watch it cold or hot.

Did you find your problem? I answered your P.M. to me but didn't hear back so I assumed you got things squared away.

I wish I could say its fixed. I put the new cutout on and for some reason after a fifteen minute run and then a stop the car battery was dead[amp meter showed 12 amps while on this run]. I jumped it with another 6volt battery and it started. I checked the 3 month old Optima battery and it only had 4 volts. After an overnight charge it still only had 5.8 volts and read weak on my Milton load tester. I took the battery to Auto Zone and they verified it was defective and I'm still waiting fo the ordered replacement that was to be here by sat.. When I get the new battery I'll start the testing again.
Thanks,
Bill

I think you have isolated the problem to the battery. 12 amps from the generator is about where it should be. I have a 1928 6 cyl Hupmobile but don't have a wiring diagram but if all the connections are tight (no opens) and there are no shorts (would show a discharge) and you have the proper cutout I think you will be good to go.