Self inflicted wiring problems

Hello,

     Unforunately, late last night I connected the battery in my 94 grand cherokee backwards.   I was luckly and the car still starts and drives OK.  One problem-  the power to the stereo, heat and a/c cuts off when any door is opened.  The interior lights work but they flicker on and off as does the power to  the vehicle information center.    The check engine light has also been on since this misadventure.   I have been told the the ECU should be OK since the car starts and drives. 

    thanks for your help,

                      James