Generator or VR issue?

[lizmcl527]

My '41 Dodge D20 -- a Canadian "Plodge" -- has developed an annoying electrical issue. It used to start right up and the ammeter would kick over to + to indicate a charge, and off we go. But now it starts up and the ammeter just sits there, leaning a bit to the - side until I let it run for five or ten minutes and then, if I'm lucky, the charging circuit kicks suddenly to life, and finally, off we go. Sometimes I can run it for fifteen or twenty minutes and it doesn't start showing a charge, so there we sit. No fun.

 

My first thought was a bad regulator, so I've replaced it with one of the new-manufacture ones from Bernbaum's, but no improvement shown. The generator I bought as a rebuilt about ten years ago, and it now has about 15000 miles on it. I've checked all the wiring to and from the generator, battery, and regulator, and everything seems OK, I did remember to polarize the new VR when I replaced the old one. Before I bite down and take the generator out of the car to check the brushes, can anyone think of any other issue that might cause this? And if the brushes aren't that bad, anyone got a handle on a good GDZ-4801-A generator? I don't have a decent rebuild place nearby and I don't have the kind of tools I'd need to try and do it myself.

 

Many thanx for any thoughts!

[Plymouthy Adams]

remove the band and check the brushes for clean and proper seating and NOT sticking in the housings.  My bud got a rebuild that would not work out of the box....this rebuild did not even get the brushes cleaned much less replaced, it was a paint job only.  Sadly this happens and the shop was local.  He stored it till just recently, they are out of business....gee......wonder why?

 

While there, check your connections well for clean and tight, a voltage drop test could speak volumes for you.  

Edited August 22, 2023 by Plymouthy Adams

[desoto1939]

Maybe one of the points in the regulator is sticking.

 

Rich Hartung

[Plymouthy Adams]

1 hour ago, desoto1939 said:

Maybe one of the points in the regulator is sticking.

 

Rich Hartung

then by his statement, that is two regulators with the same sticking points....

[vintage6t]

Along the same line of thinking of the brushes hanging up. As a simple experiment, start the car and give the generator some taps with a rubber mallet. If it starts charging then the brushes are probably hanging. If it doesn't start charging that doesn't necessarily eliminate the brushes though.

[DJK]

There is a test in the repair manual to verify generator output.

[D35 Torpedo]

I had the same problem and it was the brushes hanging up. Filed them a bit and it's perfect now.

[soth122003]

I had the same problem as well, but a different outcome. The armature on the genny was toast and the VR was bad as well. Found a genny on ebay and got it installed but the ear mounts were off set differently and wouldn't work on my car. Pulled the end caps of the old genny and put them on the new one and it installed fine. The worst part was a double failure at the same time. It had me chasing my tail for weeks. 

 

Joe Lee

[lizmcl527]

Thanx, all. I tapped on the generator a bit with a mallet but didn't seem to get any results. I also listened to the VR with a stethoscope, expecting to hear at least some kind of vibration or hum, but nothing. It certainly seems like the problem is in the generator itself, so we'll take a closer look this weekend...