Mystery: Intermittent Beeping on Mercruiser 5.0L

JohnBam

Recruit
Joined
Jul 11, 2022
Messages
2
Hello all,
I have had the issue for the past two weeks that I am getting warning beeps from my recently rebuilt Mercruiser 5.0L engine. I have not experienced this in previous seasons and even since the rebuild, everything is running great. I have done my research as to what these beeps could mean, but the mystery of my situation is that the beeps seem to follow no discernable pattern. Some beeps are long, some are short, some come in bursts, others only beep once then not again for 15 minutes. They have occurred at high, low and mid RPM and I have found no correlation to rough waves or otherwise. I simply cannot pin down why the beeping is occurring. Drive oil is new and topped off (I have also tried without the sensor: same result), pressure guage reads normal and so does temperature. The only thing that has changed since last season (when I didnt have this problem) was an oil and filter change. I'm lost, especially beause the engine is running better now than it ever has. Any information you all can provide is immensely appreciated.
-John
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
I'd be looking for a wire (tan/blue) rubbed through somewhere in the harness.

Alternately you could disconnect all (3) sensors and see if it still happens.

Chris.
 

Fun Times

Moderator
Staff member
Joined
May 16, 2009
Messages
9,218
Try disconnecting the 2 wire connectors at/on the ignition control module (ICM) mounted on the port side exhaust riser elbow for a minute then plug them in and go for a ride and see if the warning horn has stopped sounding off.
 

JohnBam

Recruit
Joined
Jul 11, 2022
Messages
2
I'd be looking for a wire (tan/blue) rubbed through somewhere in the harness.

Alternately you could disconnect all (3) sensors and see if it still happens.

Chris.
Thank you Chris,
Which 3 sensors are you referring to? I assume its oil temp, pressure and engine temp, but also, where would I find the disconnect for these in order to diagnose?
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Oil pressure, engine temp, drive oil reservoir level... (Anything with a tan/blue wire)
 
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