[bboy012003]

Appreciate any ones help. Bought a used and clean 2006 Mariah 21SX bowrider, no owners manual. It has two small horns under the drivers dash. Looks like one is for the depth gauge/warning, and the other one I can not figure out. The other one is constantly ringing, but I cant identify why or what system it is for. Appreciate any help!

Some facts: good 45PSI oil pressure, 1/4 tank of gas, everything charging and cooling.

[DougR]

That sounds like your warning buzzer is going off...You said everything checks out? What's your temp actually running at?

Doug

[ColoradoDiablo]

Low outdrive fluid level warning buzzer.
Check outdrive reservoir level.

[bboy012003]

Boat is cool, running on hose. I will check fluid level this morning. Thank You!

[bboy012003]

Update:
Stern Lube is full/clean. Boat has 21 hours on it. From my reading elsewhere, three things activate horn. Stern fluid/oil pressure/water over temp. None of these seem to be issues from inspection and other actual gauge pressure and temperature readings. I suspect a faulty sensor on one of the three systems. Now I need to locate sensors which activate horn and sequentially check each one by either opening or closing the circuit. Any ideas where/how many of these sensors there are? Thanks again for your help. Sincerely, Dave

[ShabahZ280]

Look for the brown/tan wire with the blue line on it. This is the alarm circuit wire. you'll have three sensors. one on the engine block for oil pressure, one around the thermostat area for engine temp, and one in the plastic gear lube reservoir. chances are, it's most likely that one. it seems to be a common problem. save yourself the massive shop bills and replace it yourself, the reservoir and sensor is all one part, and it's only about $40.

[bboy012003]

Thanks for the advice. Where is the plastic gear lube reservoir, inside the stern drive?

[ColoradoDiablo]

Inside the engine compartment on the port side on transom or side of engine if I am not mistaking.

[Motoxxx43]

If you are looking at the motor from the cockpit area it should be towards the the front right of the motor on top. The 4.3, 5.7 and 7.4s I have been around all have it in this area. I am not positive with the 5.0 but I dont see why it would be different it if is a Mercruiser.
My 7.4 was sounding the alarm earlier in the season and it turned out to be a bad temp sensor. It was 28$ and problem solved. I guess they get corroded or just dont read correctly. (there are two sensors near the thermostat- one is for the temp gauge and the other sounds the temp alarm).

For future reference:
Mercruiser Warning System & Beep Codes

[bboy012003]

Sensor on lube reservoir fixed the issue. Thanks to everyone for assistance. Thank You