I have replaced an original rad overflow tank and the rad low coolant sensor, but the light is still on.
any help would be much appreciated

 

does the light go out when you unplug the connector at the sensor?

 

Make sure the harness terminals on the harness plug are clean.You can also do the same to the two terminals at the bottom of your old sensor, just to verify if its bad or not.Ive seen quite a few buy these sensors from numerous places that winded up not turning the light off.Try testing the wires on the harness too.If the wires all pass, the sensor is bad.If your only concern is with getting the light to shut off,but you really don't need the light to warn you anyways because you keep an eye on the fluids by visually/physically checking them,simply disconnecting the harness will keep the light off.

​​​​​​(90-93)
Check the 3 sensor harness wire terminals with a multimeter and the key on.The Red/Yellow terminal should have 12volts.The Lt Blue terminal should have 12volts also.The Black terminal should be grounded.