HI WE CHANGED ONE ON AVAUXHALL CORSA THE OTHER DAY IT WAS LOCATED ON THE BOTTOM OF THE RADIATOR TO TEST IF IT IS WORKING OR NOT PULL THE CABLE CONECTED (CAREFUL NOT TO SNAP THE CABLE )GET THE ENGINE FAIRLY THEN PUT PIECE OF COPPER WIRE TO CONNECT THE TWO CONTACTS THE FAN SHOULD START TO GO IF THE ENGINE IS HOT THE YOU WILLK NOW BUY A NEW SENSOR REGARDS DRYSTONE