u/ADHDillusion

2013 Chevy Avalanche black diamond ltz.

I have this high pitch kind of hollow whistle sound coming from the vents. It's only when I have the AC on, it doesn't do it with heat. And it seems to only whistle when im at a dead stop and start accelerating. It goes away after about 10 to 15 mph.

There are no check engine lights on. Im hoping its nothing, but id like to catch it before it may become a problem.

I just replaced the AC and serpentine belt a few weeks ago, hoping that would fix it but it did not.