RZ5424 about 15 ys old. Runs fine. Had a fuse blowing issue first. Which led to lots of new switches and parts thrown at it. Two things. Release brake engine stalls, engage pto engine stalls. Has to be a safety switch issue. Tested them all good. By passed seat switch. Engine runs well, hoping to get some assistance with a clue or two as to what to check next. Also, bench tested the PTO clutch it checks good with the multi meter and the 12-volt check. What am I missing?