View Full Version : Oil pressure switch missing?

05-12-2010, 12:15 AM
Hey everyone,
I just bought a 2001 Mobius. The engine was replaced with a crate marine engine last year. While going over everything, I noticed that the hole above the oil pressere sender is empty, and there is an unattached wire dangling nearby. After some research, I've discovered that this is the port for the oil pressure SWITCH. But, it doesn't make sense.

The switch is not there, and the hole is not plugged. I figured that pressurized oil would be pouring out of this hole, but it is not. It's dry.

I traced the wire to the front of the engine, near the Water Temperature Switch, where it is rolled up and secured with a zip tie and attached to nothing.

The engine runs fine, with no warnings or faults. Full of oil, with good pressure.

1. Is the Oil Pressure SWITCH not required?
2. If it is required, and I purchase a replacement, to where do I plug it?
3. Why is oil not pouring out of the unplugged port?


05-13-2010, 10:14 AM
IM not positive on any of this but this is my thinking. Oil pressure switch is most likly for the little light by the throttle. If it is for that light then nothing to stop you from running the boat as this light is only a Visual indicator of low oil pressure.

As to why no oil comes out might be because its a pressure switch not a temp switch so it doesn't have to touch oil. It might screw into the whole and when oil in a engine is sped up via revving the engine the oil pressure goes up and then pressure is applied to the switch sensor and in return the light goes off.

Or its possible the new create engine didn't have this function and it was plugged so you see the whole but in fact no hole is really there for a sensor.

Just my thinking here as IDK because i would need to see everything to really figure it out.

05-13-2010, 02:36 PM
I am not sure about this one either. Could you post a pic of the hole and the location. The red light under your throttle is from an oil pressure sender on the V-Drive. Usually the Oil pressure sender on the block has two functions depending on the type of sensor. One would be for your gauges to give you a visual read out of the oil pressure. The other would be an emergency cut off for the fuel pump. When oil pressure drops to zero, the fuel pump will cut off. Not sure which one yours could be. Do you have an oil pressure gauge and if so is it functioning?

05-13-2010, 04:09 PM
Problem solved. Found an Indmar service representative that told me that the open port is for diagnostics, and not used for the oil pressure switch. Apparently, when the diagnostics tool in used it allows oil pressure to reach the port for testing. The unused wire terminal is normal.

Thanks for the help,