Farmall M Wiring

Hello all,
This is my first time posting to the farmall board, although I have been on ytmag on the JD boards for several years. A few years ago my wifes grandfather passed and left me his 49 M. I have only went out and started it a few times as I have been working on other projects but now I"m ready to start fixing it up. Wanted to start with the wiring as it is scabbed together and looks like it is about to start a fire. Took a look at it after also looking online about 12v conversions. He has a Delco Remy alternator on it with one wire leading up to the wiring box, also a wire drops off of that and goes to the starter button. The alternator says 1030 55a. All the 12v conversion explanations I saw online show 3 wire alternators. Also on the conversions it shows a ballast resistor to knock down from 12v to 6v at the coil...There is no resistor on this and he has a 12v coil..also no warning light light the conversions show..Wondering if he has it all backwards or just a different set up. Im not sure if it was charging before I took the ignition switch out (Taken out last year and lost, to keep a certain person off my tractor). Any suggestions on which way to put it back together would be appreciated. I have been using diagram #5 from

http://s101.photobucket.com/albums/m46/farmallbob/Farmall%20Tractor%20Wiring%20Diagrams/

Thanks, Alex

The alt sounds to me like it is a 3 wire setup. The main wire goes to thwe load side of the amp meter, the other wire (from the #1 terminal of the alt) goes to the ignition switch. There is likely to be a resistor (about 10 ohms) or a hidden idiot light, or a diode in that wire. The digram from Bob M for an alternator is correct. If it has a mag, look for Janicholson Mag in the archives. The 12 volt coil is correct if it is for use with no resistor. Jim

Theres a guy on eBay selling wiring looms for less than you can make one for. I got one for my Super M for ~$40 or a bit less. Its not much, 3 or 4 wires in a bit of cloth tubing but well put together with sealed terminals. I'd buy another from him.

This definitely just had 1 wire running to the alternator, it does have a push button switch next to the ignition switch. Friend of mine said it may be wired to excite the alternator with a push as the one wire alternator wont excite with low rpms. Also i searched everywhere and there is no resistor/ light

<a href="http://s41.photobucket.com/albums/e251/41JDb/?action=view&current=2011-08-02131940.jpg" target="_blank"> </a>

It is a one wire alternator. There is no provision for a push button "excite" If it is not charging, Tested at the battery with it running near full throttle, I suspect the alternator is at fault. The one wire systems found in auto stores are aftermarket remade 10si or similar Delco alternators with a patch inside that allows them to sense the voltage on the big post all the time.
If they are of best design, they draw just a few Milliamps all the time, running or not. If not, they can draw more and run the battery dead in a week to a month.
If mine, I would rewire it myself using a 3 wire Hitachi alternator (L terminal is equal to a Delco #1 terminal, S equals the Delco #2 terminal).
Wire it as bob"s diagram, and use small nylon wire ties to group the loom. Use #10 wire for the alt output to the amp gauge load side, and from the amp gauge to the starter switch. 00 gauge for bat cables, and 12 gauge for everything else. Use original color code, or make your own, but draw it up in a neat way to refer to and give to it"s eventual owner at some future day.
Use shrink tubing and solder on terminals for each connection.
When it is correct, then tape it, or put loom tubing on it.
I suspect the push button was used for either a starting relay (like later 400"s), or an exciter not used now, Jim