Ries,
I have just been trying to rectify the same problem on 'Alkira'.
Check out the sender in the engine block with a multimeter to see firstly that there is a circuit between the body and its terminal. Secondly, and in the same manner check if the resistance varies with temperature, (pop it in a cup of boiling water). If there is no circuit it could just be the sensor that is at fault. This seems OK on mine so I think the problem is in the meter itself.
Wiring should be straightforward. Check you have power to the relevant meter terminal with the keyswitch on and a good earth. The other terminal (this is marked G on mine) is connected to the sensor on the engine block.
Knowing the price of genuine Volvo spares it could just be cheaper to replace the meter and sensor with either a Vetus or VDO unit. Vetus have several in the range or you could try VDO on
www.vdokienzle.com. (go to marine then instruments).
Regards,
Frank Fowler, V1775 'Alkira' Liverpool.
