farmall h 12volt gen system

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farmall h 12volt gen system

Post by dtoots1 » Fri Aug 04, 2017 7:23 am

Stan Disbrow and any other knowledge please...

this was last converted to 12 volt alternator with coil etc....too big to fit under hood and literally got broken off..luckily broke the aluminum b4 anything else....

now he has a 12 volt generator so i need to get it set up correctly, engine been rebuilt and all repainted...still has resistor on it...need to check coil see if it has resistor built i need to see just how this thing gets wired up to ignition switch, ammeter, generator etc...

my jd40 wheeled is still set up for 6 volt generator and assume that would be basically same for 12 volt gen...unfortunately the v/r is under the switch panel and hard to follow wiring...same with my farmall cub..tho that v/r is actually mounted on or near the gen.

also gotta remember to energize the gen and should that ground be setup as positive ground for the 12 volt just like the 6 volt or can it be set up negative ground...all wiring is new and lights are 12 volt.

suggestions please

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Stan Disbrow
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Re: farmall h 12volt gen system

Post by Stan Disbrow » Fri Aug 04, 2017 4:19 pm


Most 12v were neg gnd. The change from pos to neg gnd came about at the same time as the change to 12v.

That said, there *were* some things that kept on with pos gnd with the 12v change. I don't recall any IH 12v pos gnd, though.

Wiring ought to be from batt thru the switch to the cutout on the reg, then from the reg to the field coil on the gen. Gen can be polarized either pos or neg gnd, and it will be the particular regulator you have that determines which. Probably neg gnd.

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Re: farmall h 12volt gen system

Post by shinnery » Sat Aug 05, 2017 12:01 am

Most all alternators were built to be used as negative ground. If your IH was used for a while with an alternator, it is probably wired to be negative ground and no good reason to change it now.
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