Engine sound

Does anyone know what this weird sound is coming from and how to fix it ? It seems to be more quiet when ac is on but not completely quiet.. It started today when i was on a mountain road trip ..M13a engine manual 2002

It comes from the front of the engine near the outside belts of the ac 

Good grief, that’s a good (in a bad way) sound!
No idea as to the source, but a mechanics stethoscope or screw drive placed (carefully) around the engine is a very good way to locate the source.
Alternatively disconnect the AC and Alternator belts and have a feel of any rotating parts. Start and see if noise has gone, if it has it’s going to be something driven by the belts, ie  alternator, water pump / cooling fan / AC unit  / idler bearing

Agreed that is not as happy noise.if it's less with the air-conditioning off it's kinda suggesting that magnetic drive clutch on the AC is dying but it's like said above, you need to eliminate everything in turn.

I just found that is the ac compressor and its rattling when rotating.. do i have to change all the ac compressor unit or just the rotator thing for the belt ? 

The AC pulley (rotor?) is made up of two parts,  The outer on which the belt runs and a second part connected to the compressor shaft. Between the two is an electric clutch that connects the two.
AC off then only the outer is rotating with the belt.
AC on then the outer and inner are coupled together, hence the AC shaft turns.

So it you rotate with the AC off, checking that the inner part / shaft is not turning, does it still rattle?

If yes then it sounds like the problem is the electric clutch, aka the pulley. You can take it apart to check for rust or damage. I've seen a few pictures on here of someone doing this, but can't find at the moment.