This switch was bad when I bought my boat and the PO had just bypassed it with a jumper to let the fuel pump run when ignition is on. This switch just cuts off the fuel pump when oil pressure is too low. I assumed this switch was bad so I replaced it with a switch from SKIDIM that is actually an Indmar part.
http://www.skidim.com/prodinfo.asp?number=49-6007 This just converts it to two wires instead of three.
Switch works fine for 20 hours and then dies while I'm out on the water. Luckily my cousin was out in his boat to tow me to the dock. I figured it was this switch when I didn't hear the pump run while cranking so I bypassed it with another jumper and everything runs fine now.
Why would this motor kill these switches? My oil pressure gauge seems to be working fine and the motor hasnt seized up yet since I've had the switch bypassed so I imagine I have oil pressure. This switch resides under the distributor at the back of the intake manifold on my '98 Carb'd motor.