russ is sure to have you an answer...
he is 173abn and he not only has the same Grasshopper, but recently had to go through his wiring for a problem in his starter ckt.
Your problem will be most likely related to the seat switch (operator present switch) that ultimately keeps fuel held on to the rack...
some diesel engines use a fuel shut off system and others use a fuel held on system... either one will work, but they are wired slightly different...
so I hope russ will see this thread and tell us which of the two you have...
It is important that you allow these systems to be fully functional on your diesel powered mower... :smile:KennyV