I felt like the Kt745 Command 7000 Series 747 cc engine on my Bad Boy Zero Turn mower needed a low oil pressure safety shut off. These engines come with the feature if they were sold for a stationary application, but don’t offer the functionality on mowers, even though I know my older mower with a Kohler v-twin had the feature. The engine harness already has the wire for the switch.
I installed the pressure switch and tested to figure out what kind of control circuit it needed to allow for startup. (at start up, there is no pressure for the first few seconds). I settled on adding a new relay that isolated the switch while the starter is engaged, then adds the switch to the motor kill circuit after the starter is not in use. Here are the schematics of the new relay along with the other relays.
