I have an intermittent problem with my 2000 xk8. When I turn off the ignition key I notice that all my electrics have stopped working. When I remove the negative lead from the battery and reattach it everything returns to normal. I also note that the negative battery lead is very warm to the touch as if it is drawing high current. Possible bad relay??
Also I was driving the other day with the a/c off and the a/c indicator light came on and the fan but no cooling air. It went normal a few moments later and has been forking fine since.:icon_s crewy::icon _screwy:

 

I assume it's the clamp for the negative lead that is hot (hotter than the positive)? If that's the case, that points to a bad connection at the battery. These cars are very sensitive to battery condition and the quality of connection at the battery. If you can sort out the bad connection at the battery, the rest of your problems may disappear.

 

The first I would do is go round the car and make sure all the ground points are clean and tight.

 

The battery cables are known to fail at the cable crimp, even when not obviously corroded.

 

Similar issues, I replaced the main battery ground clamp, available from any auto parts store cheap. Solved the issue.