Yanmar Water Warning Light / Buzzer

[theonecalledtom]

Jack - I've just been sorting out an overheating problem. This came down to crimping in the fresh water system. Found new senders in a $30 package from defender.com (includes oil pressure and water temperature switch AND buzzer unit).

You may be frustrated now but when things start working again you'll know your motor much much better and will get a nice glowing satisfied feeling!

[markgoldfarb]

I have read through many of the posts and have not found a mention of a warning buzzer that beeps occasionally. I am not able to determine what it is beeping about. Any opinions?

[Badsanta]

You may have a broken wire to a sensor. As it flops around, it connects the circuit causing the intermittent buzz. Check the wire to each sensor. Or the sensor is right and signaling low oil pressure, over heat or what ever and because the wire is broken (could be hidden by the plastic covering) and then it will temporarily connect giving the short buzz. The sensor works by closing the circuit causing current to flow causing the alarm to sound. Most probably a short to ground. But finding it is the rub. Good luck.

[Cheechako]

I had an older Yanmar 30 hp in my Hans Christian that showed overheating pretty much all the way from Trinidad to FLorida. Unfortunately I wasnt aboard for the trip. Various mechanics worked on it, water pumps were changed, thermostats etc, nothing provided a permanent solution. Once back in florida we discovered it was the sending unit! Buy a digital thermometer and find out if it really has anything wrong with it.

[senormechanico]

I too, have not read every post in its entirety, but FWIW, our Yanmar 3HM35F would occasionally overheat when we were motoring at cruise rpm. 6 knots, alarm. 5 knots no problem.

It was due to barnacles on the Maxprop.

Steve B.