2 beep then constant alarm Mercruiser 4.3 mpi

[jayoel]

Audible alarm at around 2800rpm before plane when leaning on port side. Drive oil, temp, oil switches were disconnected without any resolution. Took to shop and I was told raw water psi was low. So water pump R/R without solving alarm. Oil psi 30 idlle 60 WOT. Water temp 140. When constant alarm sounds throttle down alarm resets. Alarm is very random. Only happens when leans to port side. I removed single post wire on oil and water switches separately and gauges went out. Removed sender 2 wire plugs separately and unable to start.

 

[alldodge]

Always post at least the year of the motor and serial numbers are best

Reviewing previous post from 2023 I think yours is a 2015 motor??

I might be the in gear switch on the shift plate. If you have Bravo drives then there will be one switch, if they are Alpha then there are 2 switch's

Disconnect the in gear switch switch

 

[jayoel]

Serial# 2A438744 I have power loss when constant alarm. I never have any issues with engine shutting off? Also, I am curious when I disconnect the single post switch why I lose my gauge on both oil and water when I disconnect the two wire sender for both oil and water. I am able to crank the engine, but will not start.

 

[alldodge]

I have power loss when constant alarm.

Agree, there is power loss "IF" the motor thinks the drive is not in gear

I never have any issues with engine shutting off?

ok that's good, but this was not part of my comment

Also, I am curious when I disconnect the single post switch why I lose my gauge on both oil and water when I disconnect the two wire sender for both oil and water. I am able to crank the engine, but will not start.

Because ECM needs those sensors to run.
Thanks for SN you have a motor with CAT exhaust

 

[jayoel]

Agree, there is power loss "IF" the motor thinks the drive is not in gear


ok that's good, but this was not part of my comment


Because ECM needs those sensors to run.
Thanks for SN you have a motor with CAT exhaust

 

[jayoel]

I will check gear switch. I am just baffled to why it happens only when boat leans to port side so it would be best to disconnect the gear switch as soon as the constant alarm comes on, correct

 

[alldodge]

It probably just needs to be adjusted.
Don't know if you have Alpha or Bravo, but Alpha is easy, Bravo not so much
If Alpha with motor OFF, move throttle forward about 1/2 and then 3/4 way. Note where the switch is and difference between idle.

If Bravo, you have to do it with motor running because a Bravo should not be shifted without motor running

Can disconnect switch after motor starts and before or after going in gear

 

[jayoel]

scanned and getting 23-2061. Replace raw water sensor with 8m0157752 Also checked ground pin out of sender and then 5v from both pins from plug. To no avail getting same issues. Also if I put 5 people in boat the issue gaurdian mode happens quicker that with 2 people. Grrr

 

[alldodge]

Has the impeller been replaced?

23-2061 is low water pressure

 

[jayoel]

Has the impeller been replaced?

23-2061 is low water pressure

End last season 50 hrs ago I guess that’s the next item to replace again

 

[alldodge]

Normally they last longer then that, unless something like a plastic bag gets caught on drive, sucked up some sand, to many rpms when run on a hose