I installed a Delco 0380152 CD player in my 1998 Pontiac Grand Prix after the tape deck went out because I didn't want to change the interior appearance. This weekend I tried installing a USA Spec PA11-GM45 and everything seemed to go well except that I can't get it to play from the iPod. I thought I could just click the "CD" button to switch to the iPod but this doesn't do anything. There is no AUX button.

The Delco 0380152 has a plug on the back which I believe is for a CD changer and which is what I plugged the USA Spec device into.

Anyone have any experience in this area?

Specifically, for those with this type CD player, how do you change to the CD Changer discs? What buttons need to be pressed?