Mercruiser 7.4 Oil Pressure Alarm Goes Off Randomly?

[CLi87]

I have an alarm that keeps going off randomly, sometimes I run the engine and it'll never go off, other times it starts buzzing and doesn't stop, I think it's the oil pressure sensor anyway, it's got a white with blue stripe wiring going to it. My oil pressure gauge on the dash reads perfectly fine right at about 40 psi and my oil level is right in the middle. Does this engine have 2 oil pressure sensors like the thermostat has 2 temp sensors, one for the gauge and one for the alarm?

 

[alldodge]

Don't know which 7.4 you have but yes your motor probably has 2 sensors. One is a sensor for the gauge, and the other is a switch for the alarm.

Same can go for the Temp gauge and switch. The drive lube bottle can also cause the alarm to turn on. Many times it is the lube bottle.

Next time it goes off, disconnect a lead from the lube bottle, then oil switch, then temp switch

 

[QBhoy]

Agree with AD…usual suspect to rule out is the gear oil header tank low, if you have one. That’s most commonly setting the alarm off randomly…if it’s just on the edge of low. Perhaps you have already ruled this and overheating out as not to blame though.