Jaguar Repair: 85 XJ6 instruments, fuse panel, test light

Question
Sir,
I have a 1985 XJ6 and the instruments work sometimes and then quit (tach,speedo,gas etc.  Any ideas on where to start looking?

Answer
Hi Kim,
All of those instruments share a common fuse. You must test it with a test light or volt meter at the time of failure. It is #4 fuse (15a) in the main fuse panel. It can be that fuse or a wiring connection to or from that fuse. It is no use testing when they are operating.
Howard