Generator Help Needed......please

I need generator help. I'm using a 36-39 ford generator converted to 12Vs and using a 40amp voltage regulator. the car is completely rewired with good clean connections and grounds. the generator is grounded good to the block and to the regulator.

the problem: the generator intermittenly charges, but more often than not, it doesn't charge. i'm using an amp meter. the amp meter is normally showing -5 amps (electric fuel pump draw), and when its not its bouncing from -5 to +10 amps. When i put my voltmeter on the system it just shows battery voltage.

when i jump across the field and battery terminal on the regulator it charges fine, producing 40amps at 14.3 volts. no intermittent charge.

i've replace the regulator twice with no change, i used a known good regulator from another car. I've checked every connection.

Any ideas......besides using an alternator.


thanks, Tim

 

Check the ground on the regulator. My diagram shows the field going to ground through the voltage and current relays, via the case.

 

Make sure your regulator is a match for the genetator. Ford generators and regulators are mostly "B" circuit meaning the generator charges when the field is fed positive, Delco or GM generators are "A" circuit they charge when the field is grounded. As the last poster said make sure you have a complete ground circuit with a ground from the generator to the regulator.

 

Thanks. The regulator is a ford type for negative ground. Grounds are good. Generator and regulator are grounded to the same terminal, also connected to the battery ground.

 

Start with the generator ID...what is it?? Pictures??
Does it have two studs in case, Field and G-ground, and Arm on rear cover??
If so, case and innards are later, like '41 up...if no G, '38-40...I ***ume this is two brush. Next do you have source and PN for the regulator to try and figgerout if Ford type circuit...
Also I think 30 amp is the base one, no idea if higher amp ones would have difficulty in understanding a low amp gen,

I posted a bunch og en tests here: http://www.jalopyjournal.com/forum/showthread.php?t=278956&highlight=generator+testing&showall=1
Though I think your jumping test says that gen is good and problem is reg or wiring...

 

Thanks Bruce, Sorry, no pics yet.

The generator was originally a 3 brush "cutout" generator from a 38 ford. A shop in Oregon converted it to 12 volt and a 2 brush unit. The shop installed a field post and the arm post is still out the back of the generator.

the regulator is a 3 point style borg warner unit from O'Reily. I've tried 2 different ones. I don't have part # handy but it is for an early 60's ford.

Will a mid-60s solid state regulator work. I still believe the problem is with the regular.

I rechecked all connections again and system charges steady and strong when regulator is by-p***ed.

 

Tim, Did you polarize the generator?

 

Yep everything polarized.

and good news, problem solved. I tried 3 new regulators. then i tried a regulator off of my neighbors 56 ford truck that hasn't ran in 10+ years, and everything works great. its not the original, but the inner guts look alot better than any new one made.

it charges great, charges when lights are on, no intermittent issues.

thanks for the help and comments.

 

Also, (after checking out Bruces post) run a separate ground wire from you frame or body to the regulator brkt.