Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Do you have a voltmeter to test the system? There is a fuse shown at the left side , near the front of the engine compartment , but it should not keep tractor from starting. Do you get any indication there is voltage to the keyswitch? Lights in dash on? Glow plug lights up? What is actual battery voltage? Are cables clean and tight? Full battery voltage to the starter solenoid from the battery?
Also look for a fusible link near the starter, many times it will be in the ground wire, looking like a solderd in fuse.