Volvo: Volvo XC70, windshield defroster, volvo xc70

Question
Hi, I have a quick question.  My 2004 XC70 will make a loud squealing type sound whenever it is raining and I turn the front windshield defroster on, or have the air blowing up by the windshield.  Should I assume that this is some type of belt or pulley?  It just seems odd that it only happens when it rains.  Thanks.

Answer
Chris,
Your noise is one that would need to be hear and traced before knowing what the noise is. I can not think of why a belt would only make noise when it rained and defroster on. Your going to need to have a tech look at the car when this is happening. Not a real easy task. Sorry there is not a short and better answer.