VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Adjusting generator amps

My generator is putting out like 20 amps when at 30mph---pegged on amp guage,can someone tell me where I can find a diagram or instructions on how to set it correctly? JYD suggested my manual but I do not see anything about this in my literature. Iwas told that there is a printed diagram on how to do this but have had no luck finding it. All help greatly appreciated,Thanks

There is a screw on the back of the generator that holds the third brush position . Loosen the screw move the brush . If you move the brush holder ccw while looking at the back , this should decrease the output. Dont forget to tighten the screw on the back.

The procedure on how to adjust the third brush on your generator should be in your repair manual, and we have also discussed it many times here on Chevy Chatter as well.

Anyway, remove the generator cover band. There is a round head, slotted screw on the outside of the rear end frame of the generator near the flippy top oiler. Loosen the screw a few turns. The brush that is on top side of the generator is the third brush. Move the third brush towards the engine to reduce the output of the generator until the output is around 8 to 10 amps at driving speed. Be sure to tighten the round head screw when you are done.

Thanks Skip & Jack for that info. I did spend an hour this morn trying to search old topics as I was certain there have been many posts about this over the years,but,I am not that good with the site nav. for sure!!

Okay....let us know how you make out with the generator output adjustment.

Generator adjustment picture from Bills's site.
http://1931chevrolet.com/specs11.htm

Thanks for the Diagram, that helped me tons to UNDERSTAND and truly VISUALIZE what JYDog was describing.

Sure this is something I will check once I am done with my brakes and back to fine tuning the engine to take out the 29 for the Maiden Voyage !!

OK ---heres the latest fellas ! It would appear that MY Delco Remy generator is not the original as there is no little door to remove as shown in the diagram! That is probably why I could not follow JYD's instructions to adjust the 3rd brush! The only thing I see to gain entry to anything is a huge slotted screw in the middle of the generator body,directly above the "delco-Remy" tag. So, am I still not getting this right or is it possible my generator is a different model? I tried to loosen that huge screw,but my largest screwdriver (14" long) would not budge it !!!

Got a Model Number ?? maybe post a picture of what you have ??

I am heading back to garage now to see what info I can get off the darn thing ! Thanks everyone for your help ! I am feeling pretty stupid here right about now !!

Jay, that huge screw is one of the screws holding the field coils to the generator body. You DON'T want to loosen that unless you're replacing the field coils. If you could read the model number from the Delco-Remy tag and post it here, someone will certainly be able to help you out. A photo or two would help, too.

All the Best, Chip

There is no "little door" on the generator. Access to the brush area is gained through the "cover band" which is a band that goes all of the way around the circumference of the generator case.

The correct generator for your car is a Delco-Remy 943 J.

Don't know why you would want to try to remove the pole shoe screw on the side of the generator to gain entry to the brushes since the brushes are in the back of the generator.

O.K. I tried to do as you instructed JYD,BUT did not see any "band" anywhere! Also no screws anywhere! SO I looked at the diagram posted by jack39rdstr(thanks Jack) and I see, what appears to me to be a small access door which has been removed ! Take a look at that Skip and see if it looks like an access door to you.
I try not to be to lame,but,having NEVER worked on any generator before,I am somewhat lost in the sauce here.
The generator is Model #1102779 and Serial #2C28 --at least that is what is stamped on the oval Delco-Remy tag!
Maybe that will be of some help to those of you are trying to help me out here---its all I got! Also,ABOVE the D-R tag,stamped into the case is the #1110.Thanks again for being so patient with my inexperience everyone.Jay

The area shown in the diagram is not an access door.....it is an open area in the generator case for access to the brushes. As mentioned above, the opening is covered by a "cover band" that goes all of the way around the generator case to cover the two open areas (one on each side of the generator) in the generator case that are there for access to the brushes. You might want to refer to your shop manual since the generator and the brushes are shown in the manual.

Based on the model number that you posted, you definitely have the wrong generator. Your existing two-brush generator is for a much later application and it uses a voltage regulator. The original three-brush generator (a model 943 J as mentioned in a post above and featured in the diagram) had a cut-out that sat on top of the generator. Later generators used a voltage regulator instead and the voltage regulator was mounted on the firewall.

By the way, one of the applications of the 1102779 generator is for a 1951-52 Buick.

Well,that explains that,thanks JYD. So,the next thing I know nothing about would be the voltage regulator. I am assuming that is the black box on the firewall,maybe 3"by4" with three posts and three electricial lookin things inside?
I guess what I need to know is,how can I adjust the amp output on this generator/voltage regulator setup---if its even possible? Thanks again from the rookie !!

Yep.....that black box thingy on the firewall is definitely the voltage regulator.

Regarding the adjustment of same.......DON'T TOUCH IT!! If it needs to be adjusted take it to a generator shop and have a professional adjust it for you. However, since your electrical system is controlled by a voltage regulator, and if it is doing the job intended, I would suggest leaving it alone.

OK ---I'll leave it alone! That being said,the fact that the amp meter shows the system charging a +20 at 35mph and +10 at idle should just be left alone or do I need to turn to something else to reduce to the reccomended +2-3 at idle and +10 at 35mph or is it ok as is? Thanks again! Jay

If you don't reduce the charging rate you will boil the water out of the battery and ruin it. Best to hook up a working regulator so the charging rate can be controlled or find the original type generator.

Thank you all for your help. I will drive over to the ol garage and have someone that knows what he's doin get it done right...

If the voltage regulator that you have is working correctly it should cut the amps back as needed by the demand of the battery. If it is doing that I would not attempt to adjust the voltage regulator. If the amps stay constant at +20 then you will definitely need someone to either adjust the voltage requlator or check out your charging system.