Ok, here it goes.  I've replace the battery, voltage regulator, starter switch, generator, and rewired the tractor with the wiring harness kit.  Prior to putting it up for the winter I replaced the voltage regulator.  I did this because my amp meter needle would run at the max, and when I would turn it off the needle would drop into the negative.  Only after tapping the voltage regulator would the amp needle set back to zero.  Also the battery kept draining after every few days of running it.  I attempted to adjust the amp meter by turning the screw on the generator but the amp needle never changed.  A few weeks ago I uncovered the tractor, replaced the generator and threw the battery in and it would not turn over, not a sound, nothing.  I charged the battery and still no luck, the tractor was dead.  I bought a new battery and still nothing, no sound, no attempt to turn over.  So that's when I replaced the wiring harness, and the starter switch.  Today I pushed the starter button and nothing, no noise, no attempt to turn over, nothing.  The only thing that happens is when I turn the key the amp meter drops into the negative, other than that, it just acts dead.  Where should I trouble shoot next? 

Any help would be appreciated.

Thanks
Chris

Thanks for the help Pete.  My tractor is a 9N.  We bought it from a friend at work who said that it was a 1939.  He bought it from a family in Lancaster who told him it was a 1939.  But the data plate on the motor is so worn that I have no way of verifying unless anyone knows of any other serial numbers on the tractor itself.  I haven't been able to find any. 

I do have another problem.  I replaced the voltage regulator this morning because every time I shut off the tractor the amp meter would read into the negative (usually around 10-20amps).  I would tap the voltage regulator and the needle would go to 0.  When I shut off the tractor today the needle pointed into the negative (Around negative 30amps)  I taped the voltage regulator and the needle went back to 0.  So what other problem could it be if it wasn't the voltage regulator?