I want to put my stereo system into my new 2003 s40, so i went and bought the harness and antenna adapter. after i plug in the harness, my cd player powers up fine and played the cd's. now here is the problem: radio mode did not activate the antenna(no big deal cuz i dont like the radio anyways) but only the two front tweeter's in the dash work. i checked the radio settings for balance and fader and they were centered. i had assumed the round plug in the back of the stock radio was for a factory pre-wire cd changer but now i am being lead to believe i may need to bypass and amplifier system..... somebody please help!!!!! the only harness to harness wire i did not crimp was for the remote because i have not even attempted to run my power/ rca cables yet.. i stopped progression and started researching.... i reinstalled the stock radio no problem and will wait for good advice before i continue the project!

Easiest way to test for an amp would be to unplug the DIN cable while the Volvo radio is playing. Sound will stop if the DIN plug is for the amp. I would list the parts that you used to install the new radio.

thanks im going to try that and ill update with what happens... the harness i used is: metra 70-9221 (grey and green harness plugs) and the antenna adapter: metra 40-vl10.