Why does my temperature gauge not work?

The most common cause of faulty temperature readings is a broken coolant temperature sensor (CTS). The part, which is normally located near a vehicle’s thermostat near the base of the radiator (consult your owner’s manual or repair guide) can get gunked up and fail. Disconnect the temperature sensor’s wiring connector.

Why is the temperature gauge on the dashboard not working?

Thus, the temperature gauge on your dashboard is your window into the coolant temperature as seen by the temperature sending unit. It lets you know when the engine is cool, at operating temperature, overheating, or fluctuating. The sending unit is a thermistor. It is exposed on one side to engine coolant.

Why does my temperature gauge read hot and cold?

If it reads approx. 140 Ohm (or more) when the engine is both cold and hot then the sensor is faulty and needs to be replaced. If the sensor reads 30-50 Ohms when the engine is hot then there may be a problem with the wiring back to the gauge or with the gauge itself.

What should the temperature be when the cooling fan is turned on?

The cooling fan should start running at approximately 230° F (110° C), which usually happens after 20 minutes of engine operation. If the cooling fan doesn’t turn on, it will lead to overheating. Compare the temperature of the engine head, near the thermostat, and the upper radiator hose.

How can I tell if my coolant temperature sensor is bad?

To diagnose the coolant temperature sensor, you need a repair manual for your car model to find what measurement values you should expect from the coolant temperature sensor. Connect an OBD2 Scanner and look for related trouble codes. Check the live data to see the temperature from the sensor.

What should temp be when cooling fan does not come on?

NOTE: if the cooling fan doesn’t come on when the engine has been operating for 20 minutes or more, make sure that coolant is reaching operating temperature, around 220°F (104°C). You may be dealing with a stuck-open thermostat.

Why are the fans running but not the temp sensor?

The issue is in the temp sensor circuit. The fans running is because the ecm does not see a temp sensor so it assumes a hot condition. If battery disconnect solves the problem it is resetting the ecm (engine control module; i.e. computer). I will try it as I thought it would be an ecm issue. I have the same problem. I replaced the temp sensor.

Why is the temperature gage on my a / C not working?

A/c was blowing cold air for a few minutes then stopped blowing cold air but blow motor was blowing hot air. Next the temperature gage was not working. Disconnected battery for a few minutes and reconnected and the temperature gage is working and the a/c appears to be working.