Blower Fan Debris?

With the help of this forum I recently replaced my blower fan resistor and cleaned out the fan assembly also (again). It has always had a problem with leaves and pine needles working into the fan from somewhere. I just returned home from a week long visit where the truck was left parked unattended for 5 days out in the open near some trees. When I started the fan and A/C lots of noise and vibration came from the fan area. A check revealed what appeared to be an entire bird or mouse nest down in the fan. Cleared it all out and now everything is working fine. Any idea where this debris is entering the truck's blower fan assembly? My 2005 4-cylinder did not come with a cabin air filter although the door on the fan assembly would appear to accept an aftermarket one. Okay to add one? Thanks.

 

I had the same problem. What I did first is remove the windshield wipers. Then the cowling. I then used 1/4" galvanized screen to minimize the possibility of critters entering the air intake. Then I used plastic screen to stop most of the debris form entering the air intake to the fan.
I took a regular house vent and modified it to fit the intake. On my intake there are two holes on the flat that I used to secure the vent.
To apply the plastic screening to the wiper cowl took a lot of time. I think there were 5 sections of different shapes and sizes. I used plastic door screen because it was easier to flex and mold to the cowl. To initially secure the screen I used loctite super glue and different size and weight sockets to keep the screening down long enough to cure and hold the screen. This process took a long time. But, I was not done. I then secured the perimeter of each individual screen with fast cure epoxy.
This was completed more than a year ago and has kept my cabin air filer free of leaves. This also cut down on the leaves from building up on the inside of the front wheel wells.
I do not have pictures. I looked at the wiper cowls of other vehicles and most have screens.

 

Thanks - good to hear my truck is not the only one to have this problem. I remember when I once had the dealer clean out the fan assembly ($47.00 - I have the receipt) they asked if I was parking in a field. Now I know why.