2003 Optimax 200hp steady alarm?

[NLaudy]

Went out trolling for stripers over the weekend and we trolled for about 5 hours without any issues. Then all of a sudden I heard my alarm go off. It was a steady tone for about 20 seconds then turned off. I checked the oil, checked that it was still peeing, and all was well. We trolled for another hour or so and it came on for about 5 seconds before I turned the motor off. I starter her back up again and wasn't getting an alarm. Started trolling again and about an hour later it went off with a steady tone for roughly 45 seconds then went off. I continued trolling and about 25 minutes later it came on again for a few second and then the noise stopped.

After that I trolled for about 3 more hours without any issues. Then as we got done pulling all our lines in, I shut off the motor to pull the planer boards in about 4 miles from the boat ramp. When I went to start it back up the alarm came on making a steady noise. No beeps... just a steady tone. I checked everything over and everything still seemed good so I drove it back to the boat ramp with the alarm.

I looked it over prior to doing this and the oil was good, water was coming out pee hole, the water was cold and plenty of pressure. The engine also never went into guardian mode (limp mode).

I checked the warning codes and I never saw anything about this. It mainly mentioned warning beeps but this wasn't a beep. It was a steady alarm when it came on.

When I came home and flushed the engine... the alarm never sounded!

Anybody have any ideas on this?

 

[huntinfool]

Sounds like the over heat alarm. Usually from a weak water pump or scale build up in the reeds. I don't know if that motor has the reeds, so it may be a thermostat problem. If you're running your motor the water from the pee hole should be warm/hot.

 

[Captain Ahab]

Overheat. Check intakes for weeds etc.

 

[RiverBottomOutdoors]

I'm voting overheat too.

 

[NLaudy]

Thanks all! That gives me some stuff to look into!

 

[NLaudy]

Okay I am really struggling with this... I spent all day working on the boat. Some of the stuff I thought would be related to the issue and others just needed to be done. I have done the following:

- Replaced the lower gear fluid.
- Replaced the water pump.
- Replaced the three (3) in-line filters.
- Replaced both Thermostats.
- Pulled all the water lines and checked for clogs (didn't find any).
- Pulled the strainer in bottom of engine and it was in good shape. I just cleaned it up.
- Replaced all the spark plugs.

I am still getting the steady alarm. I turned the key on the boat and it did the regular single beep... I then cranked the engine and she fired right up. Within a few seconds the steady alarm came on. I turned the motor off.

Now when I go to turn the key it does the single beep followed by the steady alarm...

Anyone have any ideas? Could the alarm itself be bad maybe? Can't even find it on any of the diagrams.

 

[NLaudy]

Nitz, thank you for the information!

I think I am making some progress with this issue. I took a good look at the temperature sensors and noticed the one looked kind of funny on the negative cable. I disconnected this sensor and the alarm went away. I plugged it back in and the alarm came back on. I am assuming this means the sensor is bad so I ordered a new one. Would you all agree with that?

Here are some photos...

Messed up negative wire:


When connected, the alarm comes on.


When disconnected, the alarm doesn't come on.


Respectfully,

Neal.

 

[NLaudy]

Just wanted to give a quick follow up. Received the new Air Compressor Temperature Sensor and replaced the old one. That looks to have solved my alarm issue. Took the boat out for a few hours last weekend and it never came on