In Reply to: Re: 6 volt positive ground? posted by K.LaRue-VA on May 16, 2018 at 16:53:13:
Yes, battery cables are part of the wiring and both are so important to the electrical system, yet often overlooked. I have and always will say that non-running/non-starting issues with these old N's is 99.98% due to some sort of cobbled up 12-volt switchover job. The daily posts on the tractor boards are proof alone. To avoid confusion, I will add that only the first 9N-10000-A generator used a voltage regulator, then obsolete with the 9N-10000-B unit, as the round-can cutout circuit was released. The round-can cutout was used up through 2N production, then with the 8N model released in July, 1947, a new generator and voltage regulator were used. A VR can be used on a 9N or 2N IF the generator has been changed to an 8N unit. Otherwise a 9N-B and/or a 2N generator must use the round-can cutout in order to function properly. I have worked on several wrong non-starting configurations, including tractors with 12V batteries plus the cutout and sometimes a VR connected as well. I've had 6V 8N's with correct generator yet a cutout installed and no VR. I've had and have seen many N-Series models using Model A car generators. These are obvious as the round-can cutout is mounted on top of the generator. I also have seen tractors with early V8 generators -wrong on various levels, one being the output could be up to 85 amps. 9N/2N gennys should only be 7-11.5 amps. When Ford engineers designed the 9N tractor, it was all relatively new. they originally tried a Model A type genny with cutout then determined that the tractor needed a more robust, sealed unit as it was exposed to the elements greater than a car set up. There is a photo in most of the Ford tractor books of a prototype 9N tractor with a Model A generator mounted on it. For some reason or other it was determined the new tractor needed its own generator with a voltage regulator. I still find this as an odd decision because we all know Ford was a frugal man and demanded that parts already in the pipeline be used across the board in multiple modules. The round-can cutout was one of those parts. It's ironic that they soon, by early 1940, discarded the 9N-A genny using a voltage regulator and opted to go with the cutout circuit. There were severe charging problems with the early generators. Changes were made fast and furious to correct that -i.e. switching to a cutout, using different size pulleys, etc. when part of the true root cause was those early units had no tensioning device to keep the fan belt tight and the genny charging. There was only the mounting/pivot bolt on the units which, under load, would loosen up on their own and thus cause the non-charging issues. Ask any old timer how many times they were stranded in a field at the end of the day or sooner because their tractor battery was dead. It took Ford engineers a few years to realize this and thus came up with a belt tensioning device to keep the fan belt solidly secure. The device was standard on the new 2N-10000 generator and a kit was available from the dealer to install on the previous 9N-10000-C generator. The 9N-C and 2N gennys were virtually the same except for this part. The device will not work on the earlier 9N-A and 9N-B gennys as they have smaller barrel diameters. Some farmers realized the problem before Ford did and came up with own tensioning devices too. The later 8N generators, 1947-1949, on tractors with the front mount distributors, used a totally different tensioning arm, P/N 8N-10145. I often see this part missing on 8N generators too. Anyway, here's a LINK to my article on the early 9N/2N generators. It is so important that one understands the why's and how's of the electrical systems on these Ns. Simply swapping out the original 6-volt battery with a 12-volt battery does not now make it a 12-volt set up.