Thanks for clarifying and confirming that one oil pressure switch is normally open and the other normally closed. It's important to know the switches are different when troubleshooting and to have the correct part numbers. The updated schematic I have also verifies the wire colors you list although it's often difficult to confirm with all that red paint
. The schematic shows one side of the auxiliary oil pressure switch (#11552) connected to TB2-8, which isn't connected to anything else. When I am back on the boat
I will try disconnecting the auxiliary switch while the genset is running, which should have no effect. Thanks.