Coolant Temperature Gauge and Sender The coolant temperature gauge operates based on the amount of current flowing to ground via the sender at the engine.

For example, the water temperature sending unit can be tested for the proper ohm rating with the engine cold and then running at operating temp (thermostat open), or you can remove the sending ...

Sending units, be they temperature, oil pressure, or fuel level, are all variable resistors. They control current flow to ground, which affects needle position at the gauge.

A vehicle's engine coolant termperature sensor plays a significant role in preventing overheating. Here are four signs that it has failed and needs replacing.

09. At left are the sending units for the coolant (water) temperature and oil pressure gauges. The box in between is the Sky Drive GPS unit.

The coolant temperature sender works the same way based on coolant temperature and thermal expansion. When the coolant is cold, resistance is high and the needle rests on Cold.

I have recently replaced the frozen thermostat in my 2011 Ford Territory 2.7 diesel seven-seater. After 24 hours of appearing to have fixed the problem, now I have the temperature needle flying from ...

Depending on the make and model of the car, oil temperature, coolant temperature, and engine revolutions per minute (RPM) might be included in the dash’s readouts as well. But around these gauges are ...

It might be a case of super-fast overheating, but one would expect the temperature needle to take more than 15 seconds to go from normal to dangerously hot. You could have a broken or faulty gauge, a ...