Its an EP85 you have Wayne yes? If so you are looking a GT sensor to suit your wiring loom. Easy way to double check, pull the plug off, if the fan runs you want a GT sensor, if it doesnt, connect the plug to earth and if it runs you want a Glanza or UK Starlet sensor.
That might explain a few things then, as it does stay on when you unplug it. So although I have a ep91 engine because I have a GT engine loom I need to get the switch from a ep82?