Thanks again Stefan, I have just got rid of all the oil sensor stuff and I will need to run a return wire to the engine to ground it as I have too much wood in between.
The switch I have ordered is this...
https://www.ebay.co.uk/itm/313824236361?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649
And is labeled as heavy duty.
I was wondering if it was on the low voltage side, I can't find the video but below is a report of this on the U.S CK site....