My 97 dakota sport is making a rattling sound in the front of the engine, and on the left side when facing it from the front. i think its the air compressor for the a/c. but it sounds like its inside the alternator or near it. but i doubt its the alternator. please help. its driving everyone in my house crazy.

Put a stick on or around all the pullys,and put the stick to your ear.The pully that is making the most noise is your problem.That is the quickest way to find out where it is coming from.
Or you can buy a mechanics stethoscope.