A possibility to check is to see if leaves and debris have gotten through the fresh air box, the grate in front of the windshield wipers, where it goes down into the blower motor.
Disconnect the battery and then remove the lower box cover the get to the fan. Remove the blower fan and see if a bunch of leaves, etc. Come with it.
If this is the case the box should be cleaned out while you are at it. If you have a shop vac, use it to suck out as much of the box from under the dash as possible. IIt is the build up of leaves that you heard rubbing on the motors blades.
After years the air box gets debris in it and startys to get into the interior heater box. The other problem, which is more important, is to check the weep holes that are at either end of the box and exit right above each front fender.
After time they will get clogged. When this happens rain will not be able to drain out of the box through the weep holes and evebntually back up and flood into the interior.
The best you can do here is an air compressor with a blower tip on it or a high pressure washer. The best way is to take the fenders off and clean it properlay and make sure they both drain.
Wednesday, November 9th, 2011 AT 1:14 AM