The PO disconnected the oil pressure switch on my b6000 and removed the bulb. The tractor fires up nice with no visible issues. I know enough not to run it very long since I dont know the status of the oil pressure. Since I dont have a bulb, I have taken a meter to the switch while it is installed and it seems to show OPEN (not grounded) when the tractor is both running and not running. So can these switches fail in the OPEN (good oil pressure) state? What is the part number for the replacement switch?