greybeard
Herd Master
Seat switches on any mower brand made by MTD are easy to trouble shoot. It's a normally open switch, meaning the contacts in the switch are open (off) when operator is in the seat. If in doubt, unplug the 2 wires where their terminal connects to the seat switch and the unit should start and the pto switch should work if the problem is the seat switch. On many non MTD mowers (Kubota for instance) the seat switch is a normally closed switch. On those, to trouble shoot, you would stick a U shaped wire into the seat switch terminal to jumper it..for testing only of course.