Hi, I have an annoying high pitch sound that occurs only when I turn on the A/C (which is often in Houston TX). The volume of the whine is fairly quiet when it starts then increases in volume, then fades, then increases continually. Constant whine cycle of low to high to low pitch is about 5-8 seconds.
Any suggestions?
Thanks
Patrick

 

In the cabin or under the bonnet?

 

The noise is in the cabin from behind the steering wheel/instrument cluster