Crazy idea?

Mebbe I shud jest leave things be... But here goes my crazy idea. I have a Ford 9N tractor. The hydraulics that raise the arms of the 3 point hitch system are powered by the same system that spins the PTO. This means that when the post hole digger is kept raised it also must be spinning. This is dangerous but that's the way the 1939 tractor was made. The tractor is a 6 volt system. I have a 12 volt clutch that I am thinking about interposing between the PTO and the post hole digger. The clutch draws about 5 amps and the generator can put out 11 amps. So what if I arrange, with some sort of switching, to have the generator connected in series with the 6 volt battery to power the clutch whenever I am using the post hole digger? Crazy idea? I could change the tractor to 12 volts but that would require a new alternator, battery, and coil. As well as the kit to make an alternator fit the tractor. Since the battery and generator are new I can't justify to myself that replacing them needed to be done anyway so why not convert to 12 volts. Since I have a machine shop the mechanical part can be done properly. But just because I can engineer and build the mechanical part doesn't qualify me to judge the electrical part of my scheme. Thoughts? Thanks, Eric