So I just replaced my alternator and now for some reason when I turn on the A/C I get a loud clicking noise. Not sure if it is comming from the alternator or A/C compressor. Anyone have any idea?

 

If you only hear that noise when turning on the A/C, I think you've narrowed down the problem

is your A/C still cold? could be the clutch plate in the A/C.
you could get your alternator tested and eliminate that from the list of potential suspects

 

Is it that common for an alternator to make noise? The sound, sounds like a clicking or rattling. I also notice I get it when I put the car in gear, just not as loud. The A/C does still work fine.

 

Sounds like something is loose. Double check your work.

 

Could it be the bearing in the A/C compresser, even though it sounds fine when the A/C is not engaged?

 

alternators usually whine.