I just read the instructions. It recommends a PS9or equivalent oil pressure switch be part pf the power circuit. Is that already part of the circuit or do I have to add this in? If I have to add it I will need instruction to make sure I wire it correctly. Here is a pic of the instructions, it is one page. I expected more specifics. Like is the black or white wire supposed to be the power?

ACDelco EP42S.jpg