Classic/Antique Car Repair: a jag, jags, 6s

Question
all i know is it has xj on the back of the car

Answer
Hi Andy,
There are XJ-6s, XJ-12s, XJ-Ss and XJ-8s. All completely different cars with completely different designed electrical systems and completely different engines. Nothing is the same on any of these Jags. And to add to this there are even different designed electrical systems and completely different engines in the XJ-6s.
So look at your registration to see what kind of car you have.
Howard