After a 20 mile drive parked the Jag, returned 2 hours later and the Red warning light was on the Fuel Guage and the Temp gauge and intermittently on the transmission shifter . The Ignition was completely dead no lights nothing ,no headlights no readings would not turnover , the Trunk would not unlock manually or with switch.
Returned 2 hours later and no red warning lights and full power car started first time .
Suspect maybe a combination of the Valet and or low battery on the Key fob as it was also un responsive .
Any feedback ?

 

check battery connections in the trunk.

 

Corrosion on the PCB of the instrument cluster causes a host of odd electrical problems--that might be worth checking, and there is a video on YouTube on removing the cluster; doesn't seem too hard.

There is a Service Bulletin on the corrosion issue (but I apologize that I don't have it handy...) A quick search will produce it.