812 Generator Old vs. Late

Let there be no mistake --- I ALWAYS enjoy reading the Forums (Fora?) no matter what the subject may be

I agree, as much info as possible is very important. The service bulletins are still available though the ACD museum.
Josh's outstanding book on the subject is out of print and is now a collectors item, selling for more than $200 used.
Even with all this info a new owner can be overwhelmed with the mechanics as they are all proprietary to the Cord. Auto parts stores don't stock parts and most mechanical repairs can be very complicated.
If there are some unanswered questions, I will refer to this web site as an area of most reliable information.
On some questions I will find info on a similar part used in another type car. A lot of questions are generic as sanding armatures or metal types not covered in the factory bulletins. There may be a Cord factory shop manual I am unfamiliar with.
If all the newsletters were in a data base a lot of questions could be answered. There were so many production changes. Those would be interesting chat topics that could be discussed in the forum in the future.
I enjoy postings when other members share there experiences doing everyday ACD repairs.
That is why when someone posts a repair experience, no matter how simple, such as changing a wheel with a stubborn lug nut, or rebuilding a drive unit, it is very interesting reading no matter how many times the story has been told.
Sometimes I have to sit through long, boring tech meetings at work. They review things I might have seen before. I rationalize the time spent because I usually can learn one new idea that can help in the future.
I often say to my self, "How come I didn't think of that"

Chris, it's true that some owners may not have a copy of basic materials like the Service Manuals when they first buy their Cord. But they are doing themselves a disservice (no pun intended) by not securing these easily available basic source materials soon afterward.

The forums are wonderful places to raise questions, share and ramble, as you say, but it seems to me that they should supplement, rather than substitute for the basic materials.

This three generator brush generator issue was and still is a mystery to me. How the fields are energized, just amazing.

I was sharing the few articles I found pertaining to these generators. I was hoping someone else had experience with these to share.

There is a three brush on my 6v Harley that has run well for over forty years and never considered it unusual.

Of course there is no load on a motorcycle except the headlights but the 6volt battery never ran down and I could push start it if needed.

I did not see the 812 generator retrofit in my service bulletins. It would be an important section and had I seen it I may not have gone to the trouble of learning about these three brush and have just mounted a shunt type with a regulator on the firewall.

I thought the shunt type generator required another type late model 812 wire harness. please post the data if you have a wiring diagram of the changes needed with the field armature terminals.

I am glad for the forum as I just learned about the retrofit. I don't want to waste any ones time or megabytes of bandwidth.

I would never ever change to 9volts or run an alternator. Maybe if I had a new $900 "genernator", possibly, but I am having a lot of fun with the old generator.

It is like having a tube radio, heck there are more reliable transistors, but then there is no amazement as when it actually has a vibrating sound, glowing tubes and sound coming from an ancient speaker, wonderful!

Josh Malks wrote: Guys, the information you are looking for is clearly spelled out in the Service Bulletin to dealers regarding the shunt generator retrofit that is in the collection of Service Bulletins that every Cord owner should have...Please read the Manual. Thanks.

SHOULD have doesn't mean they DO have it. Which is why we share and ramble about these things in the first place.

Guys, the information you are looking for is clearly spelled out in the Service Bulletin to dealers regarding the shunt generator retrofit that is in the collection of Service Bulletins that every Cord owner should have. There is no need to debate generic solutions or upload huge files. Please read the Manual. Thanks.

Hi, these large files are sure to crash my photo server for 24 hours.
I was not aware there was a 37 factory retrofit. I searched for an 812 diagram to see the difference between the 810 at the generator hookup. There must have been an accessory harness or they made up hookup connectors with 12ga cloth wire.
I found this simple diagram to show how a generic firewall mounted regulator hookup.
Remember the buss-bar mentioned in the factory bulletins?
I have not see one but mine has a side knob that does the same purpose.
The reason for keeping this generator is that it runs fine at under 20amps.
This seems like a lot of problems but the shifter harness at the column for the shifter is many times more complicated.

I think you're misunderstanding, Tom. Both Cord years had a regular. The 810 third-brush gen had a two-charge (TC) regulator sitting on top of it like a little hat. The 812 shunt type gen had a separate reg mounted on the left side of the firewall. Dealers could retro-fit.

Josh

Oh Lord, I have had enough trouble forming sheet metal repair parts, and now I have to understand this generator! Ahhh--that's part of what makes this car so wonderful. No wonder I never found a regulator among the parts.

Thank you for your posting.

there several more pages on shunt if anyone is interested I can scan them.

Interesting 1929 electric nomenclature chart I thought you may enjoy.

Mark, do you have the Cord Service Bulletins collection? Much on this subject in there. (MORE books for you to buy.)

I used to wonder how to tell if my battery was overcharging.

I knew I had to advance my third brush because it was charging slowly and the headlites were dim.
I found this list below of things to check, was this clue under Battery,

"The battery shold be checked frequently and the plates covered with distilled water. When a battery requires excessive amounts of water, it is probably being overcharged. The charging rate of the generator can be changed. Vaseline spread around battery posts will prevent corroding."


So from this quote I would assume one way to assess overcharging is battery water usage. Its easy to forget checking water as the battery is under the seat. Also today most twelve volt batterys are sealed.

Thank you for the help on this question. It appears that my car was produced in mid January of 1937 before the break point of the late style generator/regulator configuration. With the addition of the schematic, I am pretty much set on the proper course to take . You folks are the best.

Mark Tomei
ACD Club Member

Hi. My car 812, 1752 has the same generator. It is a three brush generator.

Cord installed shunt generators with the regulator on the firewall in 37. There were many renumbered 36's that were sold in 37 so the firewall would not have been drilled. Do you have a intake mounted fuel pump?

My old body 1752, was mentioned in the old service bulletins as existing on the factory floor in 1936 and having the shift detent installed and it has the early drive gearing and the shunt generator. I guess they exported the dog cars on the assembly line !

I have the early steering wheel but no cowl fillers. I'm sure it was not modified so it must have been early on the factory floor and then built and sold in 37. I has the 37 Bendix backing plates.

I like the three brush generator because it is so vintage. It works fine and I should be able to keep it running for the foreseeable future. It has plenty of output and as long as I dint run the radio and heater and lights at the same time for long periods I should be OK.

The old generator may need service and they will overcharge in warm weather but I have a spare armature and they are readily rebuilt.

There is a cutout to prevent overcharging on the regulator.

I have some old literature on these generators and I would like to have more info on them also. They were phased out in appx 1936 in most car manufacturers for the slightly more powerful shunt type.

The third brush controls the field windings voltage. The shunt regulators points vibrate to give a more regulated output. This is a really complicated topic and I am still trying to absorb some of the info. The subject it discussed in some car encyclopedias but they usually stay on the later generators and alternators and not three brush generation.

This is a most fascinating topic and there was so much known about electrical generation in the thirties, there are HUNDREDS of pages in prewar manuals about this seemingly simple subject.

There are armatures, windings, adjustment, breakers, poles, low speeds, brushes, regulation and constant-current, plus many other methods.

My SC Phaeton, 31737 H, is considered to be a mid to late production car. It however has the regulator on top of the generator. Inspecting the firewall, it does not appear to have ever had mounting holes for the unit. Is this acceptable in show standards? Was there a cross over period where both were used? I have a suspicion that this is covered in Josh's book but unfortunately haven't found a copy for myself as of yet. Thanks!

Mark