1930 Delco Remy Generator Question

[hursst]

Hello,

  I have a disease that makes me want to put everything on my 1930 Plymouth back to original.  So, I took the working 943J  Delco Remy (early 30's Chevy) and replaced it with a 943R, which is the correct model for my Plymouth.  The "new" 943 R was a junker I found on this site and had to be restored.  I took it to my local generator guy.  He built it as a fixed-brush system as that's what he said it had when I brought it in.  He did a great job restoring it, but when I re-installed it, it didn't work, the amp gauge read a constant -2 Amps.  I called him about it and we discovered that he rebuilt it at negative ground.  He didn't know it was positive ground and I forgot to remind him.  He converted it to positive ground.  I put it back on the car and same thing, -2 Amps at all engine speeds.  The Chevy one was working fine about 4 weeks ago when I took it out of the car.  I did a test a friend told me about from the Cadillac club magazine to disconnect the battery at the positive terminal (positive ground) and if the car stops running, that means the generator is not producing anything and that the car is running purely from the battery.  I did the test and the car stopped running immediately.

 

  According to the original owner's manual, this should have been an adjustable system with an adjustable third brush.  The Chevy one I had on there before had this system and I had it dialed in very nicely.  I believe my 943R would have been an adjustable 3-brush system originally and that someone must have converted it.  The screw for the adjustable portion of it is still there, but the rest of the mechanism is gone.

 

  So, my question to the group is, can a non-adjustable system even work on a 1930 Plymouth with a cutout switch, 6-Volt system?  Any ideas on why the system wouldn't be working?  If not, I was thinking of shipping it to an early generator specialist to have converted back to a 3-brush adjustable system.  Please do not respond with "Just put the old one back on, why would you change it, moron?"  Don't forget, I have a disorder, I want the 943R original one on there, in the spirit of the AACA.  Other thoughts?

 

Thanks!

Chris

[Spinneyhill]

OK, cynical answer...... Replace the barrel on the 943J with the 943R barrel. The rest of the insides will be the 943J parts. And it will work!

 

Many makes and models of vehicle used the 943 in one guise or other. There must be minor differences in them, but what? Pulley size? Brush holder arrangement? My Dodge 8 has its original - it was made in Canada. But have seen other Dodge 8s with their original generator, also made in Canada, with different suffix letter. I am wondering what these small differences are and if they changed the generator "model" during the vehicle model run. Mine even has a pressed steel pulley with the two sides spot welded together; others have a cast pulley with spokes.

 

One thing I noticed when I cleaned mine up was the brush holders were slightly different between models, with a different spring. Mine has brush holders more like those on Remy generators of 5 years or more earlier.

 

With fixed brushes, I wonder if it needs a current regulator? The third brush did this job before, now you need another device to do it.

[hursst]

That's a fair answer.  I do not want to mess up a very nice 943J, as I know it has some value and I can resell it to a Chevy guy, so I don't want to Frankenstein anything.  Adding a current regulator or such sounds like the right answer, which means I think I'll have to have mine converted back to a 3-brush arrangement to make it right and work the way it was intended.  Thanks again for the post.

[hursst]

Thought more about your post and "subtle differences" and I noticed that my Chevy generator has a 4" pulley, whereas my Plymouth one that's on the car now has a 3 1/2" pulley.  I'm no electrical guy, but I would assume with a bigger pulley, it would turn more RPMs and generate more current.  If this is true, that may fix most of my problem and get me into positive amps, but if so, does a "fixed" brush system work okay versus the "adjustable" brush system on a car like this with a cutout switch?   Simply put, if I swap the pulleys and it gives me positive amperage, should that be fine?  Thanks!

 

-Chris

[oldford]

The two brush generator does not use a simple cut-out like before. You will have to use a three coil regulator to regulate the current. These regulators have the cut-out built into them. Not sure how the generator guy expected to have current regulation with a simple cut-out... I would take the three brush unit that was working fine and just change the Delco tag to show the model number you want. But that's just me...

 

Frank

[cahartley]

37 minutes ago, hursst said:

Thought more about your post and "subtle differences" and I noticed that my Chevy generator has a 4" pulley, whereas my Plymouth one that's on the car now has a 3 1/2" pulley.  I'm no electrical guy, but I would assume with a bigger pulley, it would turn more RPMs and generate more current.  If this is true, that may fix most of my problem and get me into positive amps, but if so, does a "fixed" brush system work okay versus the "adjustable" brush system on a car like this with a cutout switch?   Simply put, if I swap the pulleys and it gives me positive amperage, should that be fine?  Thanks!

 

-Chris

 

You have it backward.

The smaller generator pulley will make the generator turn faster......  

[hursst]

You're right, I got it backwards.  

Ok, with the info I have now, it seems I'll have to get it converted back to a 3-brush arrangement.  I don't think my generator guy understands the early stuff.  Thank you for all the posts, they have been very helpful.  So much I don't know or understand about electric.

[TerryB]

13 minutes ago, hursst said:

You're right, I got it backwards.  

Ok, with the info I have now, it seems I'll have to get it converted back to a 3-brush arrangement.  I don't think my generator guy understands the early stuff.  Thank you for all the posts, they have been very helpful.  So much I don't know or understand about electric.

Not sure you have the right rebuilder for the job.  He needs to know how three brush generators work.

[hursst]

You're right, I will not use him again for any old stuff, he does not understand them.  He does fine on the newer stuff.  I have another guy I can go to, but he's not local.  Thanks!