2000 Nitro 882 Alarm Help

[DeltaNB]

Folks,

I have searched up and down and can not find the answer to what I'm looking for, so hopefully you guys can help me out! Ok, what I have a:

2000 Nitro 882
Mercury XR6 150
SR#: 0T067432.

Engine runs, and everything seems to be normal except the alarm. From my understanding, when you turn the key the alarm should give you a "BEEP" letting you know the alarm and system is "OK". I have no beep at start up. I've checked the little buzzer module under the dash and can jump it and it works. I can also go to the engine and ground the wire to the temperature sensor, and once grounded the alarm beeps. That is the only thing I have found from the engine that will make it beep. My concern is the lack of beep at start up, and that I can not get the alarm to beep, by grounding the wires that monitor the oil injection system. (System is still on board and appears to be functional, engine runs fine, and burns oil from the oil tank as it goes). My concern is if something goes wrong with this system while under-weigh, it won't sound a warning alarm saying the engine tank ran dry, or the oil pump stopped working. (I have also tested the connection in the cap with the floater, and when the floater is dropped it closes the circuit between those wires).

I know removing the oil injection system and just pre-mixing the fuel and oil is an option, but I'd like to just explore possible solutions to the issue listed above.

Thank you in advanced for your help. I've had boats most my life, but this is my first outboard let alone my first fishing boat, and I've never been good at figuring out electrical issues. Thanks again.

Nick,

 

[Kerz]

Could be the sensor module. The following provides a summary of operation for oil sensor. I suspect a service manual will provide proper diagnostics.

The Mercury oil system has two alarm sensors. The precise history of the alarm system is not known, but is believed to date back to at least c.1987:

• Oil reservoir level: a float operated switch signals an alarm when the oil level in the under-cowling reservoir falls below about 7/8-full.
• Pump drive shaft motion sensor: a magnetically operated sensor signals the rotation of the mixing pump input shaft. This signal is sent to a separate electronic alarm module for further processing. This alarm was not in the initial implementation of the oiling system, but was added later to help detect failures of the plastic gear drive assembly.

The separate electronic module receives the signals from the two sensors, as well as from a cylinder head temperature sensor and the ignition module. It is presumed the electronic module compares the rate of signal pulses from the mixing pump drive shaft motion sensor with ignition pulses. If the ratio fall below a fixed threshold an alarm is sounded. The module provides a aural self-test-passed signal at start-up to verify functioning of the electronics and the alarm sounder (typically the MORSE CODE signal Dah-di-dit "D" or Dah-di-di-dit "B"). It sounds a built-in aural alarm to indicate an alarm signal. The cadence of the alarm is continuous for engine overhead. The alarm sounds a short BEEP-BEEP cadence to indicate a problem in the oiling system. Unfortunately this does not distinguish which sensor caused the alarm. This ambiguity is resolved by testing and troubleshooting the oil system. See the service manual for details.

There is no sensor in the Mercury alarm system which monitors oil flow or indicates a lack of oil flow.

The Mercury alarm system has no visual indicators. The aural indicator in located under the engine cowling. Its alarm cadence does not differentiate between the level sensor or the motion sensor alarm.

 

[DeltaNB]

Thanks for your info, and that seems to be the case with most of them. For my SN range, Merc replaced the old plastic gear in the pump housing with a brass one, and because it's more reliable they removed the alarm module. But they did leave some oil alarms. The wire coloring is the same (Blue/tan, Blue, and Tan for the temp alarm) [Note: this is what I find on my engine] I can't find a wiring diagram or parts diagram that shows these anywhere. The ones I do find show the wires coming from the cap for the aux tank level sensor, but they don't show them connected to anything. In addition to the alarms you listed above, it should also give you a cherp at startup letting you know the monitoring system is operational. So I'm still at a loss. Thanks for you help though.