Farmall H electrical system

Tue Jun 30, 2009 11:07 am

I have an elderly H (Ser. No. FBH-14937) that I use to mow my lawn. I've had the original generator set up to produce 14.5 volts at the generator and that gives 12volts at the battery. There is no voltage regulator on the tractor and there is a 12 volt "Cutout" on the generator. The only schematic I can find on the net is for a Super H. That calls for a 10 ga. wire from the fuse holder to the "L" terminal on a regulator. Since I have no regulator but simply a two post cutout, what do I do there? The electrical box also only has a three position switch labeled from bottom to top "O" "B" "D". I've seen references to a 4 position switch but that I don't have. Can anyone help me out or point me to a schematic that will work. What is the source of current to the fuseholder in this case? I would also like to know the age of my tractor. It runs like a top, uses no oil and the gear train howls like most well used older tractors are wont to do. I run a big 72 inch Artsway belly mower and the governor hardly ever indicates a load. PS. I've used this Artsway mower for almost 25 years to mow about 4 acres and I've never spent a penny for parts except one set of blades. Best belly mower on the market in my estimation.

Re: Farmall H electrical system

Tue Jun 30, 2009 9:18 pm

your H would be a 1940. Here are a couple of sights with H info: ... all-h.html
You have a mixture of wiring. Since you do not have a regulator with an L terminal, there should be a wire form teh amp meter to one side of the light switch to provide power to lights, and possibly ignition, if it is a distributor rather than a magneto. To tell you more about the wiring, I need to know where the F lead on the generator is connected. That is what controls the charge rate. Without a regulator, The light switch would normally have 4 positions, L (low charge), H (hi charge), D (Dim lights), and H (les dim lights).

Re: Farmall H electrical system

Wed Jul 01, 2009 9:09 pm


Welcome to the site. Sounds like you've got a great dependable tractor there. Post pictures of it sometime. As for the wiring diagram. Try the OEM Tractor Parts website, They have wiring diagrams posted there under the same section as their new wiring harnesses. I used the one in my OEM catalog deciphering my M before I got my manual and found it most helpful. The diagram was the same one as was in my manual from Binder Books.