JVC Sirius KD-LH300 CD Player "u57" Questions

...the car's audio system. I've looked at the user's manual, and I understand there is an adaptor (KS-U57) that I would need to connect an external unit. (I even think I've located the connection ...

Does not switch to Ext Input I have purchased the KS-U57 adapter to play my mp3 player through my speakers but I was never able to switch it to an aux input. -I made sure to insert a cd first -I made ...