Something really strange is happening with my 1996 jaguar XJS 4.0L
The analogue clock does not work.
However when I take the car out for a ride the clock will work for a few hours and then go dead again.
Anyone have this issue or any comments would be appreciated.

 

My guess would be that there is higher than normal resistance in the wiring or contacts somewhere from the battery to the clock itself. Likely corrosion/oxidation somewhere along the power path. When the car is running, the alternator puts out higher sustained power versus what the battery does when the car is just sitting, so it overcomes the high resistance and gets enough power to the clock to operate. That might explain your intermittent clock behavior.