Just an update. Replaced all switches and the seat relay. Engine still stops when you disengage brake. Took seat RELAY out and bridged caddy corner--with paper clip. Mower operates as it should with the paper clip. Have checked relay and it is ok. So the problem is somewhere else. Oh, I also spent about $700 and he still did not figure it out. SAD and expensive, especially when a paper clip fixed it temporarily, or maybe forever.....