Oil Preasure switch

I jut bought this XJ11 and it does run good but has some wireing problems.
There is no oil preasure switch uder the carbs. And no wire. The oil indicator light is on sometimes and out sometimes. As near as I can see the black with red stripe is the oil wire, but it has a white wire pluged in it, that goes to a switch down by the oil pan. I also have a plug in with a black wire and a red wire that go no where.
any help would be appreciated. LArry