1994 Mariner 135 Alarm Sounding

[2003Caravelle]

I've done a fair amount of reading on this subject before posting. I have a 1994 Mariner 135 that is giving me fits. Out on the lake after a few hours, started intermittent beeping (beep beep beep beep beep). Oil alarm. Shut the boat off and trolled it back. Since then I have ran it in the driveway with premixed fuel. I let it run for a few minutes, alarm turned constant. Impeller was replaced a week ago and water is shooting out of the hole in the back. I let it sit overnight and came back out today, there is a continuous beep when turning the key on now. I have unplugged the temp sensor, alarm still sounded. I unplugged all of the oil related wires going to the alarm module box one at a time. First I did the cap wires, no change in sound. Then I did the oil pump wires, one of the wires made it change to a intermittent beep and the intermittent beep will stay even if I unplug all of the wires. Disconnected the tan/blue wire that runs from the box on the port side to the starboard side, and the alarm stops. I'm assuming this is shutting off the oil alarm module itself. I'm stumped. I believe that the oil alarm module itself is bad. What is even weirder is I can turn the key and no beeps at all, turn the key off and on again and the beeping resumes.
Anyone with tips, please let me know. Since it was premixed I disconnected the oil line going to the T where the oil/gas mixes and oil was dripping with the engine running, so I believe the injector is still functional. There are no two blue wires underneath the oil tank as I read on some other posts.

 

[Chris1956]

I know a fair about the motor, but since mine is premix, just a little about the oil injection. Your motor should have an overheat sensor and temp gauge sender, one on each head. Make sure to disconnect both for testing. They also should not be connected together.

I will assume the motor and boat oil reservoirs are full? You might check the reservoir float sensors for proper operation.

A lot of folks would advise you to go premix, as the oil injection system has a bad reputation for failure.

Sorry I cannot help more......

 

[2003Caravelle]

All tanks are full. I think I may just bypass the oil pump for now. I would rather be safe than sorry.
I disconnected the oil alarm module (tan/blue stripe wire running from the box on port side to the terminal on starboard side). This turned off the alarm, and from looking at it I don't see anywhere that the temperature sensors connect to this oil alarm module. Will the temperature alarm still sound with this disconnected? Just curious.

 

[Champion94]

Hi. Having similar issues with my 1994 Mariner 115hp. Owner before me had replaced the entire oil reservoir because he was having the oil alarm sound. I see that he has disconnected the tan/blue wire also...I just bought the boat earlier this summer. I have never heard the oil beep since I've owned it. Now, the constant beep is being heard. I replaced all 4 spark plugs bc they were fouled up pretty bad and did compression check which was good. Boat fired right up and ran the best it ever has since I've owned it. Pretty sure it is a false alarm. Boat is peeing and running seemingly fine. Even turning the key to run with the boat in the garage makes the constant beeeeep sound.

Has anyone disconnected the temp sensor wires? Which color wires are they and where are they located? Thanks for the help.

 

[Chris1956]

The temp sender (4 cylinder) should be on the cylinder head. The wire should be yellow. The V6 should have a temp sender(for an alarm) and a temp sensor (for a gauge), one on each head.