I have had this issue since last year but just havent looked into it yet but now i'm thinking about selling my house... When my A/C unit outside (Heat pump?? my blower and coils are in the utility room in the house) turns off there is a very loud screeching sound that happens for approximately 2 seconds. every time. It is very loud, you can hear it from at least 50 yards (not lawns :) )away. This does not happen when it is on Heat.

Where do i even begin?????

Thanks in advance for any help you may have!