There’s as few threads on oil temp fitment.
I bought mine as a complete kit and somewhere there is a schematic for a blank on the engine block for perfect fitment
http://www.halfords.com/webapp/wcs/stores/servlet/ProductMobileDisplay?catalogId=10151&langId=-1&categoryId=165611&productId=895467&storeId=10001
I’ve got my eye on this one ?
I wired mine that way too mate. Just grab a pal and a multimeter and jobs a good en.
Really smartens up the back end especially with some face lift lights too