A word on the charging system. Those tractors are setup weird. The engine has a dual leg alternator, one side is rectified and charges the battery only at low amperage. The engine must be at full throttle and they do not charge at high voltage, maybe 13.5V. The other leg is unrectified and operates the headlights on 12V AC current, again, the engine must be at full throttle to operate the lights at full brightness. If you look, your tractor will have a two position light switch, this setup is why. Lights run on battery with the engine off, and run off the engine with it running. Do not re-wire it any different, the rectified circuit cannot handle the load.
To check the charging system, check the battery voltage with a digital meter, engine off. Start the engine and run it to full throttle. Allow a few seconds for the alternator to excite, then check your voltage at the battery with it running. Any increase over your initial reading and the charging system is working. Both of mine only run about 12.8-13v depending on temp. If you get much below full rpm, the charging stops.
Edited by Sprint 6, January 06, 2016 - 12:25 PM.