I have been having a heck of a time battling no start issues. My diesel kubota ZD21 has roughly 800 hours on it in which It will sometimes start and sometimes not start at all. When I mean not start I mean the shutoff solonoid will actuate like it should but when you turn the key it does nothing. It leaves me to beleive its a safety switch that has failed. I had sent the seat safety switch off to the company who makes them and they sent me a new replacment. I put it under the seat and hooked it up and it fired right away. Since that one time its gone back to its normal ways. Not to sure how to check to see what safety switch has gone bad? I brought it to a dealership to have them look at it and they charged me $168.00 just to tell me its fine due to the fact that everytime they sat on the seat to start it worked fine. 30 minutes later I brought it home and it would not start. Is there not a relay I can pull that will do away with the safety switches? from what I have heard kubotas relay/switch system is more complex than the average mower which makes it near impossible to do away with some of the safety swtiches.