i have a completely rebuilt 24 volt starter that as been tested twice on the work bench and works great. Once it is installed in the dozer it does nothing. Not even a click from the solenoid. I have completely disconnected all electrical except the batteries (which are brand new). I have completely cleaned the ground contact wire that comes from the neg post of one battery to the frame and the main Solenoid wire that comes from the pos post of the other battery. The two batteries are connect in series. When i jump the "S" post on the solenoid with the Hot post of the Solenoid, NOTHING.. does anyone have any suggestions.