I finally got the new relay and surveyed the various methods one could get to it. Taking
off the wheel well cover seemed to be one option and taking off the plastic shield residing
underneath the radiator seemed to be another. After a few exploratory "feels" I found an
opening that was large enough to get my arm through and reach the suspect relay. Once
found it was an easy operation to pull the relay down off it's stalk, remove the plug and
install the new relay on the plug and test for proper fan operation. Eureka! it works!

 

Randy, what year is this fellows XJ8? Just an FYI, the 98’ XJ8 & XJR was the only year (to the best of my knowledge) to have fan run on after the engine was shut off if the A/C had been running. 2-5 minutes is what I seem to recall. However, I cannot remember if the engine had been running hot that the fans would also stay on afterwards but, I’d say yes to this as well. I know my daughters 98’ XJR does this as well as several other 98’s we’ve had at the shop over the years. Yes, I’m aware that you said only one fan was on.

 

It's a beautiful White Onyx 2002 XJ8. If I understood him correctly, the fan was running when he came back
to his car after shopping somewhere. He drove it home and shut it off and the fan continued to run until it
drained his battery. He charged his battery and discovered the fan would run with no key in the ignition. He
reports pulling the fuse was the only way to shut the fan off. At this point he called me for help as we had met
and discussed these lovely cars at a restaurant where he had parked next to the Duchess. These excellent
forums provided me a great deal of information on the possible causes with my conclusion being a failed relay,
Fortunately, that turned out to be the issue and he is a very happy guy.