Hi, my water temp gauge has stopped reading, I have checked that the gauge is getting 12V and that 7V is leaving the gauge and arriving at the sensor, but how can I check which part is faulty? Any help greatly appreciated. Cheers Ray

easy - breifly earth the wire going from the guage to the sensor - the needle should shoot off into the high temp region.

If not, then gauge is faulty.

Ahh! thanks, didn't think of that, simple when you come down to it, as the sensor is just a variable earth. Thanks, Ray

actually is is a variable resistor with a negative coefficient of resistance i.e. as temperature goes up, the resistance goes down. Well, that is how most of them work.

Well regardless of how, or even why it works, it does now. Went out and got a new sensor, and all is happy again. Cheers Ray