changed factory radio with aftermarket one now message center not working properly

what year grand prix is it??? I had the same problem with my 05 ended up having to do some real rocket science to get everything to work.

i also have that problem mine is a 2000 grand prix gtp and i unpluged factory cd player and just pluged in aftermarket to make sure had right plug put the factory back in and now the msg center doesnt display anything

The 2000 is not the same system as the 04 and on. With my o5 you have to use a GM computer interface to use an aftermarket Stereo. This will screw with alot of other car features like door chimes and steering wheel controls. I ended up having to hard wire some wires and bypassing others to get everything to work like it should. ( part of that was because I bought the $39 interface insted of the $200 interface but at the time no one sold the Interface for my application)

yeah that damn system all runs from the factory stereo, i had this same problem in my monte carlo.... good job GM