Wiring Harnesses, XJ6 and XJS - Jaguar Specialties Wiring Harnesses, XJ6 and XJS. Doing the engine wiring for a Jaguar has always been a problem- even though we are switching to a more common Chevy powerplant, and portion of the original Jaguar engine wiring is usually required to do finish the job. Diagram 1996 Jaguar Xjs Engine - Best Place to Find Wiring Diagram 1996 Jaguar Xjs Engine. The wiring diagram on the opposite hand is particularly beneficial to an outside electrician. Sometimes wiring diagram may also refer to the architectural wiring program. The simplest approach to read a home wiring diagram is to begin at the source, or the major power supply.