Don't know your circuitry-- but in general -- The sensor is either open or shorted. So what I would do is pull the plug off the sensor and see if the light is one (probably will be - open circuit) then I would take a short wire jumper and short the two leads together at the plug which should simulate proper antifreeze level. If the dashlight stays on - you have a wiring problem - most likely a short which is causing the light to stay on. Good luck