I recently purchased a 2001 S80. Today, after driving for a while with the a/c on (auto), I parked in the garage, shut of the engine and went into the house. 15-20 minutes later I entered the garage and heard a fan running in the Volvo. I got inside and it was the interior fan. So, using the ignition key, I turned on accessories, then turned them off. The fan stopped.
I haven't been able to duplicate this scenario again.
Any constructive insight out there?