Another "little annoying noise" subject!

When my air conditioner is on (no other time), I can hear a little "metallic whine" in the cabin. Of course it gets annoying after an hour.

Can anybody tell me what the "wine" sound is in the cabin? I can't figure out what to look for so I can quell this latest "demon".

 

OK then, anything outside the cabin that might make a sound like it is in the cabin when the AC is turned on?

 

My guess would be the power steering pump cooling fan. The fan normally runs when the A/C is on.