Why don't the chimes no longer work after installing an after market stereo?

Over the weekend, an after market stereo was installed in my 2002 Buick LeSabre to replace the broken factory stereo. After the install, the door chimes no longer work; those chimes that let you know that you left the lights on or you left the key in the ignition. Is there anything I can do to repair this or to get these chimes working again? Or did I ruin it by putting in an after market stereo? Thanks for your time.