low volume squeaking/squealing sound from engine bay driver side

just changed the serpentine belt

still having this sound in these conditions:

1. in D shift, not in P or R (have not tried D1 D2 )

and

2. low speed or compeltely stopped (maybe I can not hear it when high speed)

and

3. I need to step on the brake

when the AC is on, the chance I can hear the sound is higher than AC off, but not exactly.

even the 3 conditions are met, there is a probability of hearing the sound

I wig-wag the pulley, and seems they are tight there

I am 90% sure that the sound is not related to acceleration.



Thanks

low volume squeaking/squealing sound from engine bay driver side