3 wire GM alternator on MF35

Chuck2

New User
Hi Everyone,
Could someone give me a detailed description on installing a 3 wire alternator on a 35.The tractor is already 12 volt.
 
A 3-wire GM alternator requires a double pole switch which your MF35 probably does not have. I suggest you use a one-wire GM alternator and not mess with changing the switch. I installed a one-wire alternator on my TO35 and it works well, however I miss the tachometer that is driven by cable from the old 6-volt generator. The plus is this tractor starts easily even after sitting for months.
 
fergusontractors dot org has a wiring diagram section under resources.

To connect a 3 wire Delco alternator:

Large stud on alternator connects to ammeter (same wire that connected to BAT terminal on old regulator.

#2 pin on rim of alternator connects to large output stud.

#1 pin on rim of alternator can connect to output of your present switch (same wire that goes to the coil). Install a diode in this wire. You do not need a new switch

Use diode rated at 1.5 amp@ 50 volts or greater such as Radio Shack 276-1661 or similar. Band on diode goes toward alternator.

The L wire on your old regulator supplied power to the light and ignition switches. This wire can connect to big output stud on alternator, or you can swap this wire to other side of ignition switch and use it with the diode. If so, connect input to switches to alternator side of the ammeter.

It would be a good idea to replace alternator to ammeter to start solenoid/battery connection with a 10 gauge wire.

With 3 wire alternator you do not need to rev cold engine to get it to start charging, it will be less prone to run down battery if it sets for an extended time, and it will probably be much cheaper than a 1 wire.

Your alternator (unless specially modified) must be negative ground. To change from positive to negative ground connect battery with negative post to frame. Turn on switch but do not start engine, and if ammeter swings to positive side reverse connections on ammeter. With negative ground the negative post on the coil goes to distributor.
 
three wires are not hard to install. You really only have one extra wire.

I don't like one wires. You have to rev the engine up everytime you start to make the alt start charging.
 
They do make a VR that will turn on at low RPM for the 1 wire alternators. We used to have a shop local that did several for me.
 
Hi everyone,Thanks for the info but isn't there 3 small wires in the plug on the alternator ? and if so how do i know which one is which ? I know the big wire from the generator goes to the battery and atleast on of the small wires is live all the time but i don't know which one.
Thanks " Chuck "
 

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