Q: My red coolant light starts flashing after driving for a while. Manual says it's electrical.

asked by on

After driving for a while my red coolant light starts flashing. Coolant is full. Manual says if car was overheating the light would stay on not flash. The radiator fuse is fine the belt driving the water pump is fine. I don't know how to check the water pump itself. I just bought this car and the previous owner said something about a sensor being bad. I'm going to try to take it to AutoZone and have it checked by the computer but any advice would be very much appreciated.

My car has 139000 miles.
My car has an automatic transmission.

If the coolant red light is flashing, then that means that a sensor is not responding to the computer system at that time. Check the coolant temperature sensor, and the coolant level sensor and make sure that they are plugged in. Remove the harness to them and check the sensor for resistance. For the level sensor, if the coolant is full, there should be no resistance as the sensor is in a closed loop. For the coolant temperature sensor, check it cold and then check it again when the engine is hot. The resistance should change. If the resistance stays the same on the temperature sensor or there is high resistance on the level sensor, then one or both sensors will need replaced. If you need further assistance with your warning lights on for the cooling system, then seek out a professional, such as one from Your Mechanic, to help you.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. My red coolant light starts flashing after driving for a while. Manual says it's electrical.

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Hard to start car, it seems flooded. Fires right up by using starting fluid.

The fact that you need to use starting fluid suggests you have a fuel delivery problem. Without knowing the year of your VW Beetle, this may tough to diagnose due to the fact that the earlier Beetles were carbureted models...

Q: Dtc light flashes and car judders

From what you've described you'll need to have the codes retrieved from the computer and have them diagnosed. This sounds like you are getting misfires and should start with checking the ignition. Also, check the spark plugs for signs of...

Q: Fans not working, and car overheats

If your fans are not coming on, that is likely why the vehicle is overheating when still. This may or may not be related to the air conditioning not functioning correctly. I would recommend having a professional technician, such as...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.