New Farmall 100 owner

Tue Jun 12, 2007 9:30 pm

Hey all! I just got myself a Farmall 100 and have a few questions. First off, when I park the tractor, should I lower the belly mower all the way down? I figured doing so would relieve any stress on the hydraulic unit. Second, a previous owner has converted the tractor to 12V. The unit will not charge (big surprise) unless I press a button they have installed. Once I press that button, the ammeter goes waaaay over to charge and it will stay that way until I shut it off. Should I consider switchig back to 6V? I would need a genny, starter, battery and what else? Do I have to change anything on the ignition? Is the 12V battery more detrimental to the points and condenser or is there a ballast resistor somewhere? I have read the FAQ's and the other info that noobs need to read.

I have lurked here for a while, and you guys are certainly the most knowledgable on IH's, so let me just say THANKS, 'cause I know the info is about to flow fast and furious!

Max Wedge

Tue Jun 12, 2007 9:49 pm

Max, it is recomended that the hydraulic cylinder be retracted when parked, which would be the down position. The button was necessary to start the alternator charging on some applications.

Teh alternator has an internal regulator, that is easy to replace if it is bad, but have you checked to amke sure the battery is charged. That may be why it charges all the time. It may still hve a 6 volt starter. so you may not need to check it. regarding the coil, it may have a 12 volt coil, or a 6 votl one with a dropping resistor.

You may want to check these wiring diagrams, they are for H/M, but electrically are the same as 100, cub, etc.

Tue Jun 12, 2007 10:22 pm

I didn't see a link to the electrical diagrams you mentioned. Can you point me to them? I really had way too much fun this afternoon mowing the grass and riding around, so I haven't had much time to check everything out. But...tomorrow is another day. Also, any idea how to decode the serial number to find out what year it is?

Tue Jun 12, 2007 10:53 pm

sorry, senility is fun. ... 065733&f=0

Wed Jun 13, 2007 2:53 pm

Max, you wrote:
The unit will not charge (big surprise) unless I press a button they have installed.

I think that what is happening is the previous owner grabbed any old alternator to put on the tractor. Some alternators are "self-exciting" at any RPM, and some won't "excite or start-up" unless they reach a certain RPM, or are "Excited" by initiating the circuit. I'm guessing that is why the switch was put in place. I'd have to go thru some my electronic books to really explain it further, but it deals with the rectifier within the unit. I'd have the unit tested at an autoparts store and see if it is really working. If not, replace it with a unit that will work with your system.

Wed Jun 13, 2007 3:34 pm

They have a alt. now made idealy for 6 io 12 volt conversion has only one wire and works as it should about $85.00 at NAPA

Wed Jun 20, 2007 6:57 am

Max, I'd check the Alt. output with a volt meter. If the amp meter never drops back, it may be over charging, The voltage should run in the range of 13.8 - 14.6, should never be over 15.0. If it's over charging, it will kill the battery quickly. It sounds to me like it probably has a 10si GM alt. that has not been converted for single wire use. How many wires are connected to the Alt? If only one of the small terminal are connected, run a jumper from the large terminal to the unused small terminal, as a voltage reference for the internal Reg.

By the way, we're almost neighbors! I live just a few miles East of Bellefontaine.

Wed Jun 20, 2007 10:29 am

that button is needed to start the alternator charging, same function the idiot light provides in older cars light came on providing voltage path triggering alternator to start charging and light went out( more electronic parts involved but light bulb was critical). check battery voltage before starting the tractor and see if it is low