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Farmall M 12V generator conversion project

D

Dennis Stuhr

Member
When my engine was restored by my local mechanic he talked me into a 12V battery & regulator but we didn"t convert the generator because I didn"t think you could hide a alternator underneath the tin. He converted to a negative ground also at that time. Without a battery charge parades & tractor drives are out of the question. So I bought a 12V generator off of a MD. Should I use the MD regulator w/3 terminals or the new 12V regulator w/4 terminals? The wiring diagram shows a 3 terminal 12V regulator. I can mount the new 12V regulator to the MD generator w/worm clamp but the old MD regulator will be difficult to mount to the MD generator. The wiring diagram does not show a cable connecting to the old MD regulator terminal marked "F". Pretty sure a cable needs to be connected to the "F" Terminal as the old MD regulator has wires hanging on it. I would prefer to use the new 12V regulator w/4 terminals if possible. Any suggestions is welcomed.
 
I personally wouldnt do a generator unless you wanted an EXACT restoration.I am with the last "poster".The Delco alternator WILL go under the hood,if done correctly.I HAVE seen some "hacks" out there who just have to cut out a notch in the hood for some damn reason???(good hoods can be hard to come by!!!!)
 
All you need is a piece of 3/8 all-thread to install a Delco alternator. You can even use the original belt. Simple
 

My 1940 M had already been converted to an alternator when I bought it, but instead of using the original generator mounting bracket, they used one of those "universal" alternator mounting brackets. I guess it worked for the guy that did it, but I never could get the belt tightened up properly without the alternator rubbing on the hood. Even tried a shorter belt, but the geometry of how and where the alternator was mounted just flat wouldn't allow the belt to ever get tight. I made some modifications to that universal bracket that allowed the alternator to set a little higher, and now the belt is "fiddle string tight", and the alternator fits easily under the hood and is not visible. I actually got the alternator position a little TOO high, and I had to "roll" the belt onto the pulley, but it works, and I did use the same belt as what is required for the original generator.
 
Yea,mine uses the stock lower mount on the engine.They modified the top adjusting mount.STILL cannot get over people that cut up them hoods!!! :(
 
Good Question Dennis, heres the deal:

Its possible to use EITHER

A 4 terminal (BAT FLD LOAD GEN/ARM) Voltage Regulator

ORRRRRRRRRRRRR

A 3 terminal (BAT FLD GEN/ARM) VR

With only very minor wiring modifications


BUT EITHER VR MUST BE WELL GROUNDED


WIRING FOR A 3 TERMINAL VR

BAT to load (NOT battery) side of ammeter
FLD to Gennys FLD post
GEN/ARM to Gennys ARM post
Loads like lights and ignition etc are fed their hot voltage from the load (NOT battery) side of ammeter, same terminal that wires down to the BAT terminal on VR.

WIRING FOR A 4 TERMINAL

BAT to load side of ammeter
FLD to Gennys FLD post
GEN/ARM to Gennys ARM post
(L)OAD feeds hot battery voltage up to to loads like lights and ignition instead of them being fed from the ammeter

Soooooooo either works and its your tractor and your choice GO FOR IT

John T
 
Pretty simple. Use either regulator. If tthe 4 terminal is used, the L terminal attaches with 10 gauge wire to the Light switch supply terminal, and from that to the ignition switch. The Bat wire goes directly to the Amp meter load side. This allows a little better voltage regulation at the battery, and is fine.
If the 3 terminal is used, the Bat terminal on the reg goes to the Amp gauge and the lights and ign are taken from there. Jim
 

My hood has gap up near the nose piece. I have a alternator 12v conversion. Does anyone else have any problems with a small gap.
 
(quoted from post at 06:38:43 07/29/11)
My hood has gap up near the nose piece. I have a alternator 12v conversion. Does anyone else have any problems with a small gap.
Click to expand...

Is it a gap because the hood doesn't quite reach as far forward as it should it? Or is it a gap because the sheet metal is slightly warped and the hood just doesn't lay down like it should?

I've seen several that are warped, including mine. A GOOD body and fender man can fix it. I attempted to fix mine, but I am NOT body man, had no luck at all, so I left it as is.
 
Since "any suggestions are welcome", IMO the easiest way to do this is to tear everything out and start fresh with new switches, a Hitachi internally regulated alternator (not a single wire), new wiring, new coil and a diode to prevent current backflow. I've done this on four tractors now (Super M, M, W6 and Super H). I'll never run another tractor with a generator/regulator set up.

So much more simple, clean and reliable. I believe I get better HP and a smoother running engine too.
 
Hey rustyfarmall here's a picture.
2235.jpg
 

I converted my M this spring with a Delco 3 wire. Flip the bottom genny bracket over and use ready rod. Fits under the hood without cutting.

Rick
 
(quoted from post at 16:36:53 07/29/11) Hey rustyfarmall here's a picture.
2235.jpg
Click to expand...

You should be able to move the grille back the fraction of an inch you need to eliminate the gap. If not you may need to move the radiator too.
 
Thanks for the input, you all had good comments. We thought we had it wired up right per the old wiring diagrams that are difficult to read. Currently have problems getting a spark when we hook up the positive ground to the battery terminal with the cut-off switch on. Sooo something's not wired right. Starter switch is turning over the motor. Is there an exploded view of the switch box somewhere? Dennis Stuhr
 
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