Farmall M electric problems

Hello Friends: I have a 1950 farmall m that was converted to 12 volt with alternator and magneto dist. the tractor was running good and when I took off the magneto to try and fit a "live hyd. pump" which didn't fit. Then I put the magneto back on and tried to start the tractor back up, something seems to be grounding back and the hot wire to the solenoid on the firewall became overheated to where the wire insulation starts to melt. I have a keyed ignition and this where the overheating starts, when I turn the key to start and connect the positive to the start negative wire on the small post of the solenoid. I have attempted to bypass with jumper cables but this also causes overheating from the battery as well, the wires get so hot that the metal contact ends of the battery cables start to melt. I took this tractor to a mechanic this past summer the mechanic tuned it up, and it was running good this tractor has always started right up in any weather. When I brought the tractor home I noticed that the mechanic had not hooked up a wire coming off the harness but the tractor was running good and starting right up. The other main wire from the harness goes from the main battery terminal on the alternator, to the ammeter, to the positive battery stud on the same side as the positive cable to the battery and the battery wire from the key ignition. all the three wires are attached to the same side of the solenoid on the firewall. The disconnected wire that is coming out of the harness has an end that leads to the alternator where the female end connector is loose not connected, the other harness wire that is connected to the main battery terminal on alternator along with a smaller gauge wire that is connected to the number "2" connection on the Delco 1s0i alternator. I live in a rural area that is quite a distance from this mechanic's garage so the towing expense is $250 one way, the wiring is not that complicated but it is beyond me what is happening I am attaching a diagram that may paint a clearer picture as to what I am rambling on about. I would greatly appreciate any advice, suggestions you can give.

couldn't get my diagram attached[/img]

Irv, the reason that you are not getting responses is that no one can possibly know what you have, because with alternator AND solenoid, it for sure is not "factory". So, unless you can post a diagram, you are not going to get much help.
If you just can't do it, e-mail me via YT's SafeMail , using Modern View where my e-mail is open. Then I will post your diagram for you.

On most farmall M if they have the engine rebuilt. You had to go to a 12 volt system useing a 6 volts starter. The six volt battery would not turn it over fast enough for it to start. There where two choices to go in 12 volts. 1. was a generator system which was used on most 1964 ford cars. 2. a Delco Remey Alrentator with a built in voltage regulator. When useing a Magneto you do not have to worry of haveing a resister on the coil to the ignition switch because it has no distributor. The altnator is basic all you need is to have these wire hook ups. B battery, One goes to the starter side. All 10-SI models: The battery termainal connects alenator out put to the insulated terminal of battery (note marked B).Number 1 terminal. conducts battery current to the rotor winding for excitation circuit and is connected to the indicator lamp or gauge. 2 terminal. receives battery voltage so that the volatage regulator can react to the system operating conditions. This should be the currect most automoblies had these hooked up in this order. Need more help let me know Brent.

You may have something locked up in the front gears after having that apart. I would pull the coil wire and hand crank it over and make sure.

The hydraulic pump off a 300 will fit a late 1950 and up H, one off a 400 may fit your M, others will know for sure.