My interior vent fan runs forever, never stops after the key is off and pulled all switches are in the off position, this just started recently.
if i disconnect the battery I here a loud relay type click in the area of the radiator when the battery is re-connected

Mark in South Carolina

 

Sounds like the Darlington transistor has failed. It's in the blower control circuit, the fan is always live and the transistor controls the power to the fan. There is a bunch in the archives about it. Some threads here:
https://www.jaguarforums.com/forum/x...ey-off-244963/
and
https://www.jaguarforums.com/forum/x...t-stop-218337/