Here is one thing on all 1000 series tractors. Behind the right rear wheel is the reverse PTO cut out switch. All it is, is the system goes to ground and then the PTO shuts off when the reverse pedal is worked. The wiring will break at the switch behind the right rear wheel. The wire harness end breaks off at the switch and then the wire will touch and go to ground as the tractor bounce around. Then the PTO will shut off, and then restart then shut off again. I can't remember the color but I think was yellow with white or Yellow with black. Wire needs to be repaired to the switch.