Alarm problem

[PAUL]

I have erratic alarm from the thermometer gageSometime at +/- 40°- 50°C or at 80°C the alarm whistle.If I disconnect the wire(few second)on the motor MD 21 (temperature sender) the alarm stops.After few minutes the alarm start again to whistle.The oil pressure and alternator are ok and temperature also max 85°C.As per today I replaced the sender on the motor and the thermometer the problem still there !!Thanks in advance if you can help me.Best regardsPaul HR 352 - N° 345 - POLLUX

 

[Jan Huisman]

Engine alarm logic

As answered to Paul directly by email I repeat my answer for others: I had a similar experience, engine oil/water alarm and nothing wrong with the engine. Later I found out that the alarm logic circuit, hidden in a small resin cast-in black or blue box, was faulty. The box is located in the wiring behind the engine gauge panel. The logic circuit makes it possible to use one buzzer for both alarms, oil & water. Volvo Penta sold me a new one and the problem was over.