1919/1920 Generator cutout

[Mark Gregush]

Speaking of cutouts, is there a replacement cutout that can be used on the negative or positive ground 1919/20 to bypass the one in the starter switch? Mine is a G unit, but working on another that maybe the GA. Yes I know that Myers has the rebuilt unit, but this is a time crunch thing. I have looked in the Dykes manual but the illustrations therein are not easy to see how they are made, if different then the normal 3 brush generators like the Model T or A. I know about the change to positive. My 20 is correct but the 1919 is wrong at this point being run with positive ground.

[MikeC5]

I believe that all ModelT and A were 6 volt systems leaving the factory.  The other option might be a diode if you can source one locally or overnight mail.  You could do some thing quick & dirty so as to not permanently change your current unit.  There are some threads on this but this one mentions mounting the diode remotely (last post)  https://forums.aaca.org/topic/153393-startercutout-relay-solid-state-conversion/?tab=comments#comment-729159

I put the diode inside the starter switch box but I did bend the original mount bracket for the relay to hold the diode and act like a heat sink (see photos).  It is important to get a diode that matches the polarity of the system on the car (pos or neg ground).  My car is positive ground and I used a 70 amp max rms diode with stud as cathode.

This thread has a good woring diagram of the SG and cut out.  https://forums.aaca.org/topic/306635-dodge-bros-starter-generator-needed/?tab=comments#comment-1713704

[Mark Gregush]

Great. Thanks. Those photos really help. True, T's and A did leave the factory 6 volts but you can buy 12 volt cutouts as a number of people convert them. I have a diode for the Model T that I have been sitting on for years. As the Model T is negative ground and I think 30 amps plus should work fine. Most of them are rated for much higher voltage then this will ever see. We had done some checking, from what we found out, the 6, 8 and 12 units all had the same rating on the diodes in the ones sold by the suppliers and they were only rated at 30 amps. For sure on the correct polarity.

Edited July 12, 2020 by Mark Gregush (see edit history)

[Mike C55]

I did see where it is popular to convert the Ts and As to 12 volt but didn't realize you can just buy a cutout already converted (and on the shelf, ready to go).  From what I've read on this forum, a 30 amp diode would still cover things.  I went with a 70 amp because it didn't cost much more than a 30 amp if I recall correctly.  It has been doing the job with no issues.