I'm looking at a 97 S90 for my son. The owner says that occasionally the interior fan will come on on its own, when the car is off. He says he puts the key in, turns the ignition switch to the on position, and then off and the fan will stop.

Any ideas?

Thanks in advance.

 

My guess it would be a bad ignition. Ignitions have several contacts in them. One of them are bad.