'84 200HP. Oil alarm self test ok, but no activation.

[donzi gt230]

I have twin Black Max 200 and both are doing the same thing. I get the long-short-short self test beeps at key on, but won't sound when the oil is low or when I disconnect the motion sensor. I checked to make sure the oil level sensors are closing the circuit and they are. I intentionally ran the oil down and disconnected the motion sensor with the engine running, don't recall which wire, but either should sound it I'd think. Are both modules bad, or could there be something with the power at the switchbox? All cylinders fire. The manual calls for using a DVA to test power at the switch, but can't find any info on what that is. I put a regular volt meter on it and get erratic readings while running, so at least I know there's something going on. I'd hate to buy new modules if that's not it.

 

[j_martin]

Re: '84 200HP. Oil alarm self test ok, but no activation.

Do yourself a favor and get a mercury maintenance manual for your engine.

Check the output of the oil alert module at the terminal strip on the starboard side of the engine, over the switchboxes. It should be high when normal, and go to ground for alarm. If it's down to start with, there's something wrong with the buzzer circuit. If it doesn't go down when the motion sensor is disconnected and the engine is running, the oil alert module is bad.

It should beep one long, and 3 or more shorts. If it quits too soon, your battery voltage supplied to the alarm module might be low, though that usually drives them completely nuts. Just for kicks, check the supply voltage to the alarm module at the above said terminal strip. (purple)

hope it helps
John

 

[donzi gt230]

Re: '84 200HP. Oil alarm self test ok, but no activation.

I have the merc manual now thanks to you guys, but I'm keeping the seloc for swatting bugs. Unfortunately there's no trouble shooting for this symptom. I guess nobody else is anal enough to test a system that passes the self test(?) I think the supply and buzzer circuits are good but I was checking so many things I'll check again tomorrow just in case.

THANKS!