After replacing the linkage that connects the control valve to the handles (H pattern / hand controlled machine) my machine will only start and run with the seatbelt clicked in. Once unclicked the machine shuts off, like the park brake button has no function. With the seatbelt unclicked it will start and immediately die. No codes are present, the seat switch on the machine works properly as does the seat belt which is also new. With the seatbelt on the machine works exactly as it should, nothing odd or unusual about how it performs. Personally I am leaning towards it being something off center in the main control valve and allowing flow to pass which would likely give me this scenario but if that is the case I need to determine the exact cause and find a solution. Any advice would be much appreciated.