I have a 97 ranger 4.0 v6 5spd with 83,000 miles. On the way to work this morning i needed to turn on my defrost. When i did i started hearing a scratching noise (seems like the fan) on the passenger side of the cab (sounds like its just under the glove box). It doesn't matter what i turn the dial to (defrost, ac, floor vents) as soon as its turned on the noise starts. I'm think the fan blade is warped and scraping against the shroud it sits in (like when you have a bent rim on a bike and as the wheel turns it rubs on the brake pads). Any suggestions or how to go about looking into this would greatly be appreciated.

 

Look under your glove box. There is a damper that opens and you can look inside the box and see the squrrel cage. You probably have a leaf or pine needle in there rubbing on the fan when it turns. I stuck a hanger in there, speared the leaf and pulled it out. Easy fix.

 

I might have to do that with my truck... When I turn on my a/c I get a humming noise form the blower motor or area under the passenger side dash.