A few weeks ago my coolant light came on and sure enough it was low. So I filled the tank with 50/50 antifreeze but it didn't seem to solve the problem. My coolant light still comes on when the engine is running at a low temperature but goes out when it'* warm. I've been checking the reservoir tank and the radiator cap and everything seems to be full. I've been told that since I didn't use the Dexter 50/50 antifreeze the sensor isn't recognizing the coolant. I thought it is because I need a new sensor. Any ideas?