2003 Saturn Vue Electrical Problem

I recently installed an after market cd player in my 2003 Saturn VUE and then uninstalled it after discovering it was damaged (I took it out of a car that had been in a pretty bad accident).

Upon reinstalling the factory cd player in the dash I discovered that now all of a sudden the interior lights, dimmer, gauges, service lights, door locks and power steering were all non-operational.

I checked all the fuses under the hood and and only one 20 amp fuse was blown as far as I could tell and I replaced it. However, the problems still continued without change.

Any suggestions on what might be the problem?