Fan buzzing/rattling behind dash? 99.5 pathy

[jokun]

I recently bought a 99.5 pathy, 100k miles. It runs great, but sometimes with the ac on it sounds like a fan behind the dash on the passenger side is making a buzzing rattling sound. It stops when the ac is turned off. I honestly have no idea what's behind the dash and was wondering if anyone had any idea what was making that sound and how I could access it.

Thanks,and great site!

[elwesso]

its probably the blower motor.... You could try taking it out and cleaning the blower motor out really good and see if that fixes it,otherwise id be looking at replacing it.