smokin' voltage regulator on Farmall A

My Farmall A was converted to a negative ground 12-volt system more than a decade ago. The alternator is an "American" brand with a voltage regulator (I,A,S,F) installed next to it. Originally, a key ignition switch existed, but eventually, an underrated 3 amp push starter switch was spliced into the system and an on/off switch linked to the magneto is used to "ground" or kill the engine after use. I have replaced the faulty 3 amp push starter switch with a heavier duty weather-proof push starter switch using the same hole from the old key ignition switch. I also bought a new 12 volt battery to replace the old battery with a bad cell. My new problem is that I"m getting some minor smoke from the "field" wire to the voltage regulator when the battery is hooked up and you hear the regulator polarize. Do I have the wiring to the regulator plugged wrong or is there a short with the orange "field" wire? It looks a bit frayed, so I have electrical tape wrapped around it, but I still need to know why I"m getting some residual smoke from the regulator. You have to look at it real close to notice. I need a wiring diagram for a 12 volt conversion kit on a Farmall A if anyone has one. The brand name of the alternator is called American. Is anyone familiar with this brandname? I"m told this brand was used on many Ford products. Is that true? Please help me troubleshoot my electical problem so I can start mowing with the Farmall A, again. Also, how can I shut off the battery without having to take the ground cable off all the time? Shouldn"t battery power only be used when I activate the new push starter switch for the starter? Otherwise, the alternator should keep things charged and I should only be using my MAGNETO to kill or ground the tractor when I"m done with it, right? Please help.

Thanks, Erin

It sounds like a typical older Ford/Motorcraft alternator. I don't know WHERE you are getting the "American" thing, though.

Is it connected up something like this:

<img src = "http://ndtc3500.stellarnet.com/~blweltin/Bob/SimpleFordAlternatorCircuit2.jpg">

If you want to keep this alternator, get it and the regulator tested, and connect it up as shown, a good SIMPLE method of making a Ford alternator conversion.

Since this is a "mag" tractor, you can sub a simple 2-terminal NO oil pressure switch for the "ignition switch" shown, which will shut off the field current when the engine is "killed", so you don't have to remember to turn off the alternator excite switch.

Another option is to go to an INTERNALLY regulated Delco alternator.

Site contributor Bob Melville has GOOD diagrams on HIS site linked below, one of which uses an oil pressure switch.
BobMs place...

The FARMALL A sure doesent need 12v. Sounds llike you have a wiring mess and i would put it back to original as those systems have lasted for 60 pluss yrs now. All of my As and Bs are original most still have the original cut-outs and work just fine and start in winter for snow removable just fine.

Smoke is the heart and soul of the electrical system, when the smoke leave the electrics die. Unless you wish the whole tractor to go up in smoke FIX the "frayed" wires, electric tape is NOT a fix, follow Bob's advice and get the reg. and alt. checked.

Thank you for your prompt response. The Farmall A is running, again. I cut off the slightly frayed end of the field wire and crimped a new end to it before plugging it back into the regulator. The tractor started like a charm. After I "killed" the engine with the magneto, there's still a slight cloud of smoke at the field wire, but it dissipates immediately. For now, I keep the negative ground disconnected at the battery when tractor not in use. Do you still recommend a 2-terminal NO oil pressure switch to be installed to prevent battery drainage when tractor is not in use? Based on how the tractor is configured, is there potential, parasitic drainage of the battery that I need to prevent? Thanks again for your advice and wiring diagrams.

Erin