Still Chasing AC Problem - Now Going After An Unexpected Noise

[thom4782]

If anyone has some insights, I'd greatly appreciate hearing them.

When the engine is running and I turn on the AC by pushing the snowflake button, there is a whine that come from front area of the the passenger foot well. I would guess that it is the AC/heater blower fan, but here's the strange thing. The pitch of the whine increases with engine speed and not fan speed.

Some I'm thinking it could be expansion valve noise. Does this make sense to anyone. It's different than the expansion value noise one hears then the refrigerant is low. It's definitely not a wheel bearing because it whines when the car isn't moving. The only way I can get it to start and stop is to push the snowflake button on and off.

So does anyone have a guess as to what else might be causing the whine. I can't think of anything up from that changes pitch with changes in engine speed.

Thanks