How to install a aftermarket radio into a 2002 Pontiac Grand Am with the Monsoon amp?

[Christian]

i own a 2002 pontiac grand am…and ive noticed that while trying to install an aftermarket radio that the door chime doesn’t seem to work, and i had my older brother do all the wiring and he knew exactly what to do but as soon as we connected the aftermarket; the power was working but when we switched radio stations and messed with the volume even inserted a cd and nothing. …but the chime only goes off when i have the stock radio connected…another thing is that i noticed a monsoon amp in the trunk left side under the upholstery…and it seems that all the speakers wires are connected to the amp…i can understand that this is why the aftermarket radio did not want to play any type of audio at all including radio/cd/aux/door chime/. I was wondering…if there is a way/ways that i can install an aftermarket radio? And how can i prepare my car for the aftermarket transformation? Will there be any wire splicing or rewiring of every single speaker? Please give me a healthy amount of information and alternative ways to installing the aftermarket radio…i’m pretty sure that the information you give me will help out other 2002 grand am owners as well… Please Reply ASAP