Motor overheating sensor

[midnight1957]

I have a pontoon with a 40 hp Mercury that I bought last year and have been doing some work on it and I am about ready to put it in the lake but I have a question about my motor overheating sensor/buzzer.
When I turn on the switch the buzzer sounds all of the time. A friend of mine told me it sounded like a short in the wire going from the sensor to the buzzer. I have disconnected the wire from the sensor and used my meter to check for it being grounded but it is not. So today I ran a temporary wire from the sensor to the negative side of the buzzer and it does not sound at all. Does this sound like I need to replace the ground wire from the sensor to the negative side of the buzzer and if I do that how will I know that if I have an overheating problem that the buzzer will work before I ruin my motor?
Any and all help will be greatly appreciated, I want to take my pontoon out on the lake and try to cheer my wife up who is fighting breast cancer.

Thanks,
Wade

 

[Silvertip]

Re: Motor overheating sensor

The negative side of the sensor is the engine block. Just disconnect the tan wire at the bullet connector. If the buzzer still sounds, check the oil level sender in the oil resevoir. The magnet tends to fall off the float thus causing the alarm to sound. If that's ok, you likely have a bad buzzer.

 

[midnight1957]

Re: Motor overheating sensor

Thanks Silvertip for your reply. When I disconnect the wire at the overheating sensor, the buzzer stops sounding. That is why I ran a temporary wire from the sensor to the negative side of the buzzer wire, when I did this the buzzer did not sound. I think the wire in the harness is shorted but I am trying to make sure that it will work if my motor should ever overheat.

Thanks again,
Wade