changed battery and kept power to car, now ac will not work, c300 2011.

This car does have a rather complex electrical system. You said you kept power to car, depending on how you did this it is possible that you might have caused a main fuse to go open. As you stated you have power to parts of the car but not all of it. Check all of the fuses first. If they check good then it will most likely need an electrical system diagnosis.

I happened after I changed the battery