In Reply to: 6 volt positive ground? posted by James Mort on May 16, 2018 at 14:28:08:
First, welcome aboard! You won't find any other place on earth with more useful, often original information on these old Ford Tractors and staffed with many helpful members. No dues or fees required but you can find a ton useful documents and manuals in our library of DVDs and such for a modest donation. We have a MANUALS forum where you can download a lot of original Ford-Ferguson and Dearborn manuals that have been scanned plus many useful documents in our HOW-RO's forum as well.
Now, to answer your questions, we cannot tell you if your tractor is 6 or 12 volts simply by a serial number. The original FORD electrical systems were 6-volt/positive ground. Many have been switched over to 12 volts, but bear in mind simply swapping out the battery from a 6 to a 12 volt unit does NOT define it as a 12volt system either. Also noteworthy to is that many 12-volt "conversion" jobs are not done correctly. You say you have a 12-volt battery AND the generator is still in place. Well, unless the generator is 12-volts, this is proof you probably have a hacked-up job too. !2 volt jobs usually use an alternator and are connected as a negative ground system -like your modern car. Then that still isn't what makes a 12-vol job right and complete. See WIRING PICTOGRAMS by JMOR in our HOW-TO's/Electrical forum. If your s/n is indeed *9N105085* then that indicates it is a 1942 9N, possibly late, and possibly a wartime 2N, meaning steel wheels and magneto and such. More later on that. As a new N-Owner, you should get copies or originals of the essential manuals required. The I&T F-04 Manual and a copy of the '39-'53 MPC (Master Parts Catalogue) are mandatory. The others are original 9N and 2N Service and Owner/Operator's manuals. We have some of these here in our MANUALS forum for free download. Here is a LINK to John Smiths' old page on ID-ing these old Ford Tractors better. Also, suggest you download the WIRING PICTOGRAMS and a copy of Bruce(VA)'s 75 Tips for N-Owners in our library as well. There is also a document of a checklist of the things to do BEFORE firing up a newly purchased tractor. You are going to want to go thru the list methodically before trying to run it and first order up getting the electrical system figured out and corrected. You say you want to keep it all original. That's fine, many of us run our N's on the original 6-volt positive ground systems with NO PROBLEMS. There's nothing wrong with wanting a more modern 12-volt system, but either way, the setup MUST BE wired correctly in order to function well. The 6-volt/positive ground setup on the 9N/2N uses a 6-volt battery, positively grounded; a generator; a starter; and a round-can cutout circuit. It will have a coil on top of the front mounted distributor - something else we will get into as we go -a keys witch and an ammeter. Lighting kits were optional so you may or may not have those, but we'll also deal with lights later. 9N/2N 12-volt conversion jobs use a 12-volt/negative grounded battery; an alternator -can be 1-wire or 3-wire; the ammeter or a voltmeter; key switch, and either the 6-volt coil or a newer 12-volt coil. If 6-volts, you will need to add an external in-line resistor to the wiring. Either way, 6-volt or 12-volt, you MUST use the original ballast resistor mounted to the back of dash near the ammeter. You can take the battery, generator, starter, coil, ammeter, cutout, and key switch to your trusty local starter/alternator shop guy who knows old Fords and get them all tested. the first crucial piece to test will be the battery. Whether 6 or 12 volts, invest in a good brand like INTERSTATE, DEKA, or EXIDE. Bargain-house batteries sold at most auto parts stores and off-shoot hardware stores usually have poor lifespans -like 2 years max. get started right with these basics and we will nurse you along. My email is open too. Good luck!
FORD 9N/2N TRACTOR ESSENTIAL OWNERS MANUALS: