Squeeling noise in 2001 Kia when using a/c or defroster?

[Erin]

When we have the defroster on, the car squeals. I think it may be related to the a/c, because whenever you have the defroster on- the a/c automatically goes on as well (always been like this). But any ideas of why? It's like 10-20 degrees in the daytime here. Not sure if it's a cold weather thing. Any ideas? Doesn't squeal if the heat is on

[parkmistyred]

Either the belt or the a/c compressor clutch that is causing the noise. Most vehicle run the A/C compressor in the defrost position. The reason for it is to dry the air coming in as much as possible to prevent it from frosting up the inside if the windshield due to the moisture in the air.

[MarkG]

I own a 2002 Kia and had the same problem. My freon was low. You can go to a car parts store and buy freon as well as a gauge and cable for about $20.