Need to test alternator on B7100

[nostep]

Go to Messicks.com. Look up parts for your B7100. In the electrical group, you can see the panel group. In the panel group there is an item #20 which is the regulator. See if you can find that behind the dash panel.

 

[Phoenix Farmer]

Look on the back side the dash for a finned aluminum block about the size of a pack of cigarettes.

 

[KubotaSam]

Go to Messicks.com. Look up parts for your B7100. In the electrical group, you can see the panel group. In the panel group there is an item #20 which is the regulator. See if you can find that behind the dash panel.

Apperently some b7100 tractors have a regulator behind the dash and some have a recitifer behind the dash. On the Messicks site if you look at a B7100D-P part #20 is listed 2 times once as a regulator and once as a recitifier. I would guess that it depends on the age of the tractor. I know what is behind the dash on my B7100 (1977 gear drive-old style) is a recitifier that changes the alternating current produced in the dynamo into dc current for the battery and lights. The voltage regulation on this type of system is built into the light switch. It is a manual type of voltage regulation. When the lights are off it is a low charge rate and when the lights are on it is a high charge rate. Kind of similar to the old Farmall tractors. My Dads Super A has a switch that I think had 3 positions low charge, high charge and lights.
On the Kubota you can not seperatly controll low or high charge unless you bypass the light switch and add a seperate hi/lo charge switch like I did on my tractor.

I have to assume that at some point in production (perhaps the new series of the B7100) Kubota changed to a regulator mounted behind the dash and the rectifying (changing ac to dc) is either done inside the dynamo like an automotive alternator or perhaps the rectifier is included inside the regulator.