Hello, I have a 2009 Z-Trak 997 Zero Turn mower, Yanmar diesel, 60" deck. I'm having problems with electrical gremlins. Engine will start up and idle, with me in the operators seat I release the park brake and the engine immediately dies. I'm pretty certain that it is a switch somewhere but I don't know where to start looking. Faulty brake switch? PTO switch? Seat switch? Directional handle bar switch? ANY help would be greatly appreciated! TIA!