H Farmall wiring......

Earlier this fall, I bought a 1944 H to go along with my other two H's and my M.

Since there was no panel mounted fuse on the ammeter box, and the ammeter never showed over a couple amps charge, I assumed it still had the original style generator with a cutout relay.

Even though the rest of the tractor is healthy, the insulation on the wiring was bad to a point of falling off and leaving bare wires so I decided to rewire it. I also decided I may as well upgrade it to a voltage regulator and went ahead and bought a new regulator. (From YT).

Anyway, when I dug into it, I found it already has a late style generator with the third brush fixed instead of being adjustable, plus it had a regulator instead of a relay. One wire by the regulator was unused. It still had the old style light switch with a fuse on it inside the ammeter box. The wiring was such a mess it was impossible to trace it out visually.

Yesterday, I simply pulled all of the old wiring off, including the light wiring, and ordered a new style light switch and panel mount fuse. Armed with the proper wiring diagrams and plenty of experience with wiring, including jet fighter planes, my objective is to build a whole new wiring harness from scratch appropriate for the new style system with a voltage regulator. I'll have to rework the ammeter/light switch panel a bit to accept the panel mount fuse. Have I overlooked anything?

BTW, having worked in Avionics and wiring in jet fighter planes where there are EXTREMELY rigid quality issues involved, I've been appalled over the years at some of the cobbled up messes I've run into for wiring on vehicles and tractors. I rewired another H earlier this year and greatly simplified a mess someone else had made.

When I got the H from my dad, the only thing insulating the wiring was the corrosion.

To my thinking, you are on track. Use 0gauge cable for the battry to Starter, and to ground to the starter mount bolt. Shrink tubing on terminal ends is best practices. I would fuse (or fuse link) the generator output at the ammeter . Looms are good, but typical plastic looms get brittle. (PET polyethylene terephthalate) plastic and other advanced polymers are more UV and Heat resistant. Jim

When I wired my Super M I pulled the wiring out of an old snowplow harness and pulled the new ones through.

That is funny, Ellis

My '54 Stage 2 Super H was built January 7th, 1954. By about 1980 I had pulled ALL the blue prints for every wire harness on it from the Engineering Dept. at FARMALL. The wire harnesses were bad, insulation crumbling, the cloth covered rubber was a terrible insulation for a farm tractor. Guy that sat next to me bought all the wire harnesses, he sent my prints off to his favorite harness supplier, about a week later he got a box with all new harness's to the prints except they had PVC insulation and the latest woven looms. OEM harnesses were terrible in 26 years, 1980 vintage harnesses are still perfect after 40 years.
Don't get hung up demanding old fashioned harnesses on your tractors. Get the newest most durable wires and looms you can find! The tractor and shed/barn you save might be YOUR'S!

As an additional safety measure, I have quick disconnects on the batteries of both my FARMALLS, and the three Cub Cadets in the shed get the hot cable pulled off the battery. The batteries last several times longer and I don't have to worry about the shed burning down.