I just bought a 1999 Ford Taurus, and when I start the car up the low coolant light comes on. I looked at the coolant reservoir and it is full. So we drove the car home, which was less then 2 miles, and the car ran fine, just this light stayed on. And the Temp of the car didn't start to warm up till we got in the driveway. What could the problem be, and how could I fix this. Also is it possible to replace the left rocker panel, which would be on the drivers side, cause its gone on the back door. Any info would help. Thank You.

Disconnect the connector to the low coolant sensor, which is located on the bottom of the reservoir. This is a common problem with Tauruses. New degassers cost around $45.

So is this the coolant sensor?

Low coolant level sensor.

Ok, I will see if this helps the prob. Also Is it possible to replace a rocker panel?