VCCA Home Forums TECHNICAL - GENERAL Electrical - 6 volt '34 generator & cutout switch questions

I have no experience with generators or cut out switches so am wondering if mine are wired correctly. I have a newer generator in my '34 (no tag) and am fairly confident my mechanic father-in-law had it rebuilt but it was not hooked up when I inherited the car.

It is a three brush unit and (unlike the original'34) has two terminals on the outside of the case. The cut out switch is connected to the terminal that goes to one of the brushes. The other terminal is grounded to the case. Is that correct? And what is this 2nd terminal connected to internally?

Also, the cutout switch has no markings for the two terminals so can it be hooked up either way or is polarity an issue?

Thirdly, I vaguely recall from many years ago, a generator needed to be polarized after installing. If so, how is that done?

When I had the engine running earlier, the ammeter did not show much, if any, charge but does show discharge with lights on,etc.

I will appreciate your replies!!

It looks as if you have a 1938-39 3 brush generator. When that is used as a replacement on a 1937 and prior the treminal is ground to the case. If you purchased a Delco universal replacement generator it came with the instructions for hooking up the wires. I had a set of the instructions but can't find them now.

So I think from your answer I have it wired correctly. But I still am wondering what that 2nd terminal is wired to internally. Also my second and third questions are still: 2. Does the cutout switch have polarity or can it be wired either way (there are no markings on the two cutout switch terminals) and 3. Do I need to polarize the generator after it is installed and how is that done.

As I said, I got the generator with the car from my father-in-law and it was not installed. There were no instructions included with the generator (or any other part of the car:).

I imagine you are correct that it is off a 38-39 since he had one he parted out.

The second terminal is connected to one end of the field coil on the inside of the generator. By grounding it, you are "full-fielding" the generator which means your generator will be charging at maximum output all the time. The cutout should be labeled "BAT" on one terminal & "GEN" on the other. On the original Delco, it was stamped right into the actual terminal. Remove the screw and washer, and you should see it. If it is rusty or greasy you might have to scrape/brush it. And, yes it does matter which terminal you use for each wire. Feel free to contact me with any questions.
Jason @ Advanced Electrical Rebuilders
www.aerrebuild.com
jason@aerrebuild.com

To polarize your generator, with all of the wires hooked up and your ignition switch off, use a jumper wire and connect one end of the jumper wire to the "GEN" terminal on the cut-out..(that is the terminal that is usually on the opposite end of the points in the cut-out). Quickly touch the other end of the jumper wire to the "BAT" terminal of the cut-out (that is the terminal that is on the same end as the points in the cut-out). You should get a spark. When that happens your generator is polarized.

Jason & Dog,

Thanks for answering my questions. To polarize the generator then I just jump from one terminal to the other on the cut out switch. That sounds easy enough.

I found the markings on the cut out terminals just as you said and it was hooked up correctly. So I have the whole thing wired correctly and will polarize it tomorrow. Hopefully, when I start it up, the ammeter will show it charging.

Thanks Again!

Glad to help out and good luck!

A quick way to polarize the generator is to remove the cover from the cut-out and press the points together briefly. Then replace the cover and your off and generating.