Before pulling the relay forever or doing something else to disable the
light you might try cleaning the two electrodes on the sensor in the coolant
pressure tank.  Also, if the antifreeze:coolant ratio is not correct the red
light will indicate a problem.  I don't know what the acceptable limits are
but either 100% coolant or 100% antifreeze will set it off.  I don't know if
this is a constant on or an on/off blink.  Maybe if you are near the
acceptable limits you can get erratic light operation.  The red light was
malfunctioning on my '86 and it was corrected by replacing the sensor as
John Meeks suggested.  This coolant level sensor is a good safety feature
and diagnosing the problem and having it work correctly is much better than
having is not work.