Temperature Gauge Not Working and Fan Running

The temperature gauge in cars is the parameter that tells about the recent temperature of the coolant in the engine. By temp gauge you get to know if coolant is cool enough to perform, hot or normal, temperature-wise.

As you know coolant is important to be at a specific temperature because it absorbs the heat from the engine and keeps it functional for mobility as heat build-up can damage the engine. So when the temperature gauge is not working and the fan is running, it means something is wrong.

Why is the temperature gauge not working? Reasons

Generally, the defect in the temperature gauge is due to a broken coolant sensor that is impacting. However there can be other cases that can affect temp gauge to not work. Such as

  • Check the coolant level, it must be at the hull hot mark on the coolant reservoir tank. However, if it’s at the lower level, the result is overheating.
  • Ideally, the coolant color is orange or green. But if the color is somewhat rusty it means there are contaminations and it can be another reason for overheating.
  • The fan running of the coolant starts at 230 degrees Fahrenheit and that occurs after each 20 min of the engine function.

Will the radiator fan work if the temperature sensor is not working?

The engine control unit is responsible for controlling the cooling fan. So when the sensor has some trouble in it, the fan will not function, and it can promote overheating issues. Therefore, whenever you notice the yellow/red light blinking on the dashboard, pull over the car and turn off the engine light.

It’s best to take your car to a mechanic for the best diagnosis. The general reasons for the problematic cooling fan are

  • Wiring Issue: When the firing is defective, the cooling fan will certainly won’t work. Check the wire first hand for finding out the solution.
  • Blown a Fuse: The fuse problem is common as radiators lean on the electrical assistance. It’s best to check the car manual for details on how the cooling system functions.
  • Defective Fan Relay: The fan relay should be in working state altogether. If it’s defective the radiator fan will get the effect.
  • Fault in Temperature Sensor: The faulty temperature sensor means no fan radiator working because it gets signal from the temp sensor.

My temperature gauge isn’t moving

The most common reasons for not moving the temp gauge are:

  • A Fault In engine coolant temperature sensor
  • Wiring is broken
  • Defective or bad Gauge
  • Corrosion in plug connectors
  • Defective thermostat
  • Air in cooling system
  • Broken engine control Unit

What to do if your temperature gauge is high?

If the temperature gauge is high it’s not a good indicator. If that happens, immediately pull over the car on the road side and let the car cool down. While doing so, don’t open the radiator cap because it is not safe. After getting the car cool down, rush to the car mechanic to solve the issues.

The high temp occurs due to overheating or coolant. Moreover, if the thermostat is broken, the temperature can be hiked up.

Why does the temperature gauge read cold?

Sometimes the temp gauge reads cold even when the benign is warmed up. The first reason is that the gauge is broken. But if you are sure nothing is broken, the possibility is the thermostat in the car is still open. 

So make sure of these two parameters. When the thermostat is crooked the temperature becomes lower and the temp gauge reads it as a low level. You should replace the thermostat if it’s lousy.

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