I have found a great diagram of the vacuum layout for the 1987 Series 3 Jaguar.

I honestly don't remember where I got this, but if anyone wants to claim it I would like to thank them. I usually get a lot of information from Captian Jaguars web site. I did down load a pdf that goes into detail about the 1985-1987 Series 3 Jaguar. The web site is hosting so much information in a easy to access way, I feel obligated to buy from him. I also feel obligated to send people his way so - Captian Jaguars Cat House