Try a search on the forum. I recently had a similar issue, and after doing a search found the easy to do instructions on how to remove the fan from under the glove compartment. I would recommend you pull the fan, and make sure there is no junk in it. If no junk, then simply order a new one and replace it. I ordered mine from http://www.isuzuparts.net/ and I believe fan was around $100. Painful cost but very easy replacement.