In Reply to: Re: My first tractor (8n) posted by Jeff on June 24, 2018 at 08:53:50:
Yes as TOH pointed out, your sketch does show it to be wired as a positive ground system. Unless you switched something, nothing wrong with it as is. The only problem would be when switching the battery ground you now need to polarize the generator so it spins the right way. That's why when doing a motoring test always apply power as it will be used as. If 6V/POS GRN, power is applied to the ARM terminal via the NEG battery connection. The GROUND is made via the positive connection to the FILED terminal. Those tires as I said are rear Turf Tires, never an original Ford Tractor item. Firestone made a similar tire back in 1947-1950 but they didn't call them TURF TIRES, like 12 x 24. The fronts are 5.50 or 6.00 x 16 style, not OEM to the 8N but offered as optional dealer accessory items. The original sizes were; F = 4 x 19 single rib style and B = 10 x 28, now listed as 11.2 x 28 style. Also as I mentioned, engine miss is most likely a carb setting issue. Get a new muffler/exhaust pipe and clamp installed. Note clamp goes on one way - The original VR was supplied by AUTO-LITE -see picture. It was their p/n as VRR-4008-A used with the 3-wire/3-brush generators with 11.5 AMP output. The 20 AMP generator used the AUTO-LITE VAZ-4008 VR. There were a few reasons why the industry switched to 12 volt systems - faster starting, brighter lights, and able to power 8-Track players...... ; > ) GRIN, and other 12V accessories like pumps and sprayers, for just a few examples. I don't think it was a conspiracy to save on costs with thinner wires/cables.
ORIGINAL EARLY 8N WIRING SCHEMATIC:
RESTORED 8N DASH WIRING & AUTOLITE VRR-4008 VOLTAGE REGULATOR:
MY EARLY 1948 RESTORED FORD 8N WITH REPOP FIRESTONE TIRES: