99 S80 non turbo. A few times over the past few weeks after i have shut the car off and come back an hour or so latrer I noticed when I got into the car the blower was going. It doesnt appear to be the fan from the engine, but the actual blower inside the car, with air coming from the vents like I had the ac on. (Which I did when I got out of the car).

 

I think it is supposed to do that to avoid mold and mildew in the vents and system.

 

it is called the afterblow function. Keeps the car from smelling funny. It won't do it all the time, certain drive time and A/C usage parameters have to be met first.