VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 38 Generator Repair

I just had my generator tested and, according to the technician, he couldn't get it to register at all. Can you give me an idea of what it might cost to rebuild the generator, or would it be a better idea to search for another working unit? If so, what can I expect to spend?

Thanks,

Jim

Was that a technician at your local generator shop? If so, ask him what it would cost to rebuild your generator.

Is your generator not working or do you have a defective voltage regulator?

You are better off rebuilding your generator instead of trying to find another correct generator for your car. Rebuilding your generator is not a big deal and your local generator shop can rebuild it easily.

Jim, here's an article about how to hide a voltage regulator inside one of those 3 brush Delco generators. It is very pursuasive in listing the benefits of making this conversion.

http://www.ply33.com/Repair/voltreg.html

I'm going to try this after I complete the 3.55 gear ratio conversion in my '36 pickup.

Since quitting VCCA and searching around for other forums where tinkerers like me submit information on stuff they've found that is invisible but improves function, I've found a lot of stuff like this.

It was on the 1936 Chevy Owners forum where I got the tip on how to most easily (and undetectably) convert my '36 to 3.55 gears by mixing and matching OEM Chevy parts of various years.

Enjoy the article!

A NEW 1938-1939 generator was offered for sale here in the last few weeks.
The original 3 brush and voltage CONTROLL work perfectly well on the 1938-39. My 1939 will maintain a positive charge with the lights, heater and radio "on" as the generator can put out up to 28 amps.

I read the article and I would like to know how the third brush allows one to adjust how the generator performs.

old216,

Here are some links on generators and third brush operation at Keith Hardy's site, which has a ton of online info.

From a 1949 Delco-Remy handbook:

http://chevy.oldcarmanualproject.com/electrical/49dr324/1g1001.htm

From the 1927 chevrolet manual:

http://chevy.oldcarmanualproject.com/shop/1927/27crm125.html

Old 216, it's probably been a year since I read that article. Here's what I remember, which isn't much. On a 3 brush generator the position of the moveable brush determines generator output. If adjusted to power the headlights, the generator overcooks the battery during the day. If adjusted for daytime driving the battery discharges at night.

On my '36 pickup I deal with that problem by leaving the lights on on long drives. I adjusted it back in the 70's and haven't touched it since so I'm vague on the details.

Also, those clunky old generators work best at really low RPMs and don't generate much current at highway speeds. As I recall the article, after making the conversion the generator output was independent of engine RPM. If true, that alone is a huge improvement.

If you want to know how the third brush regulates current, I don't have a clue. If you really want to know I can ask my son, an electrical engineer at Lockheed Martin Space Systems. He already thinks I'm from the stone age so this question wouldn't surprise him.

Motorcycle accessory catalogs list 6 volt halogen headlight bulbs and that is an attractive option for 6 volt cars, but those require solid generator output. I have halogen taillights in my street rod, a SBC Chevy powered '32 Ford roadster, and those bad boys are bright!

The ultimate leap forward would be finding an alternator so small that it could be hidden inside one of those old generators. An alternator that small would probably have to come out of a motorcycle. That, obviously, would be an internal gear driven unit, not like a belt driven car alternator. It would definitely put out some serious electricity because some Harleys I see have more lights than an 18 wheeler. That might be a challenging project, though.

To me a huge part of the fun in the old Chevy hobby is finding modern parts that work way better but are invisible. For an example of what I'm talking about see my article in the May 2009 G & D.

I hope this helps.

If anyone is interested, I still have a NOS 60U. Charlie

Jim,
Send me a PM I think I can help you out, I stay away from 6 volt generators because of the lack of parts but I picked up a lot of stuff last week
John

DanR,
thanks for the links to the articles. Now I understand how it works. What an interesting design. My neighbour was telling me how his was adjusted using thre third brush and now I understand!

Actually, many parts are still available for the old 6 volt generators including field coils, armatures, brushes, bushings, bearings, gaskets and etc.

Thanks so much for all the replies. I had a little spare time yesterday so I called a local electrical repair shop and discovered that they do lots of work on 6 volt stuff, and even still do tractor magneto repair. The repairman estimated about $75-100 to repair it; I should have it back in a day or two. I spoke with a friend who has done business with this company before and they come highly recommended. So, this should work out well.

Thanks again,

Jim