Posted 12-29-2023 at 03:35:56 [URL] [DELETE]
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Re: positive or negative ground
ALL FORD Models used the 6V/POS GRN Electrical System from the Model T on until the release of the later 1950 Diesel Tractor Models, not just the N-SERIES tractors. Diesels used a 12VDC battery power source but still had the GENERATOR and the VOLTAGE REGULATOR.
These tractors will operate on 6V or 12V, POS or NEG GRNDG. Don't assume just because you have a 6V Battery the system is wired all correctly for the 6V POS/GRN setup. FACT: 99.98% of all non-starting issues are due to incorrect wiring, regardless if 6V or 12V. Using a float charger when tractor is idle at rest in the barn is a good essential investment. As I mentioned below, the major root cause of a failed charging system is the lack of a fan belt tensioning device attached to either the GEN or the ALT. Without correct fan belt tension, you will never charge the battery. In addition, you may damage the water pump without proper cooling. FORD engineers constantly struggled with the early 9N charging system as the GEN lacked any belt tension device and relied on the pivot mounting bolt for tension. This was not effective enough as the bolt would weaken in the field and many farmers would end up at the end of the day with a dead battery. One solution was for the farmer to stop every few hours during the day and inspect the belt and make tension adjustments if needed.
Engineers didn't design a belt tension device until the 2N-10000 GENERATOR Unit. It came with an attached bracket on the barrel that assembled to a 2nd piece mounted on a head stud. SEE PIX. At the same time FORD released an optional kit for the 9N-10000-C GEN as well that secured around the barrel and composed of same parts including the spring tension bolt. This kit only fit the 9N-10000-C Unit as it and the 2N-10000 GENS are virtually the same otherwise. The earlier small 7 AMP 9N-10000-A and 9N-10000-B GENS will not accept the kit. Often these OEM brackets are missing but if you are creative you can fab your own bracket device. Some newer 12V Conversion/Alternator Kits contain a tension bracket but not all do so check your source when buying. The OEM tension bracket is not made any longer but you can sometimes find a used one on the popular auction sites.
As mentioned, polarizing the GEN is the final step after all is wired up correctly and before you apply power. It is important to know and understand the electrical system and the difference in the "A" Circuit Design and the "B" Circuit Design. The method to polarize is a quick short jumper wire arc-spark. All 9N's after 1940 and the 2N GEN use the "A" Circuit Design. The 8N and after charging system is different so don't get confused. They all used a VR.
2N-10000 GENERATOR w/ATTACHED 2-PC TENSIONING BRACKET:
2N-10181 BELT TENSION SERVICE KIT, ONLY USED FOR THE 9N-10000-C GEN:
FYI: WIRING DIAGRAM FOR ALL 9NíS AFTER 1940 THRU 2N PRODUCTION IN 1947:
Tim Daley (MI)