Tractor Repair: New Holland TC25D - wont turn over, ford new holland, starter solenoid

Question
I have a Ford New Holland TC25D and it won't turn over. I turn the key and
get one click and then nothing. I have replaced the battery and also replaced
the starter.  I know the battery is holding a charge.   I have checked amp from
ignition and also at battery when trying to start and it is fine.  I have found
and replaced one fuse and still nothing.  Any help would be greatly
appreciated; I have to jump start the tractor every time I use it.

Answer
Hello,

  The click that you hear is probably not the starter, but is the fuel shut-off relay for the injection pump.  There is probably no power getting to the small terminal on the starter solenoid because of a safety switch.  Make sure you have found and checked all the fuses besides the one that you replaced.  There are lots of different configurations depending on the model and how it is equipped.  If it is a gear drive, there will be either a neutral switch or clutch pedal switch.  If it is a hydrostatic drive, there will be a range lever neutral switch, or a switch under the hydro control pedal.  There may also be an operator presence switch under the seat.  There may also be a switch for the pto so that it can't start with the pto engaged.  There are diodes in the wiring for the starting system that could fail also.  The adjustments for all these switches should be checked, and also if there is continuity through them when in the closed position.  Any other diagnostic procedures for diodes, modules, etc. can become quite complex and may require a dealer to fix.