In Reply to: Re: 1949 8N Wire Routing posted by Rick L. on October 26, 2019 at 04:59:24:
Is system 6V/POS GRN? If you have a 3rd Brush, on any early Ford generator, there will be a 3rd Brush Adjustment Screw on the back panel. The exception is the early 9N-100000-A, was a 2-Wire/2-Brush unit, and 9N-10000-B, was a 1-Wire/3-Brush unit with the 3rd Brush on the back panel with a "HI-LO" slider push button. However, some of these 3rd Brush units were changed over to 2-Brush units and the only way to tell for sure is to inspect the guts. You do not need to convert a 3-Brush to a 2-brush. If it's as is, leave it. Have a qualified starter/alternator shop who knows Ford generators to inspect it, rebuild if needed, and adjust for efficient output. 3rd Brush use was intended to use when operator used headlights and the amp draw was greater. You'd adjust to a higher setting and then when lights not used, turned back down so as not to over charge the battery. Have your shop guy tweak your VR as well and leave it. Nowadays there is no need to adjust the 3rd Brush if it is set correctly. Output rating on the 9N-10000-C unit thru the 8N-10000-A generator was 11.5 amps. The 8N-10000-B generator released the 2-Brush/20 amp unit. There is a Service Bulletin that details how to change a 3 Brush to a 2-Brush. Your call if'N ya wanna switch. Also important to know all (except the early 9N-A unit) were the 'A' Circuit Design so polarizing the generator is simply arc sparking the BAT and ARM terminal on the 8N VR, or on the roundcan cutout, ARM terminal to BAT. It's also important to have the proper fan belt and belt tension on a generator. The 8N used a short two-bolt hole plate that connected to the mounting bracket and a governor bolt. Many of these got lost when servicing the generator and end up with no belt tension at all -the generator unit will not sustain the tension on its own. I made a dozen of these per original drawing if you want one.
FORD 8N-100000-A TRACTOR GENERATOR, 3-WIRE/3-BRUSH 11.5 AMP, ‘A’ CIRCUIT:
3RD BRUSH ADJUSTMENT SCREW ON PACK PANEL:
8N-10000-A GENERATOR w/ 8N-10145 TENSIONING ARM:
FORD 8N TRACTOR GENERATOR - POLARIZING via THE VOLTAGE REGULATOR: