'91 volvo 240 audio problems
 

Hey guys, I'm a jeep guy but my friend has a Volvo. Her speakers are extremely quiet. We usually drive aroun with the iPod plugged in with a cassette Jack. Well the stereo is extremely quiet and te radio doesn't work. My friend said it asks for a code for the radio which sounds really weird, I've never heard of that before.

Does the 240 have an amp that is shot? Or is there something wrong with the headunit?

Where can I start? Thanks guys.