I have central a/c in my house; this summer the unit outside has sometimes been making a loud, grinding noise when it comes to a stop. When a repairman came out to check in June, it didn't make the noise for him to hear so all he did was check the fre-on and said everything was okay with it.
Recently, when it does make this noise, it will now continue with a loud, metallic squeal for up to 30 seconds or more. The unit inside works properly and continues to cool. What could be causing this terrible screeching sound?
