F-series should have the same issue.

A Hoarder lives next to me. Rats!

I noticed recently that the blower motor was starting to make a drumming sound. Friday it was worse, and after about a half-hour running on VENT, I started to smell something burning. Turned off blower, put window down, smell went away.

Today I pulled out the blower motor, and found the blower wheel absolutely LOADED with foil-faced yellow insulation shreds. Some had made it through the blower, and were plastered on the input side of the A/C evaporator (could see that using a flashlight and mirror). Pulled out the resistor pack, it had shreds on it, too.

The insulation came from the outside of the A/C evaporator case under the hood, it was all shredded up, what was left of it. This is the foil-faced fiberglass that insulates the evap case from the passenger-side exhaust manifolds heat.

Looking into the blower housing with blower removed, I could see into the cabin via the open Recirculation Door. Which also meant the Fresh Air Intake door was closed. The vacuum motor on top of the blower case controls this dual door. In the "OFF" control position, the Fresh Air Intake is closed, the Recirc is open. I always turn it to "OFF" when I park at home.
The insulation got in there somehow, had to come via the fresh air path, as I did not see any chewed holes in the blower case anywhere. So I switched the control to "VENT", and the doors moved to open the Fresh Air path. Then looking down through the blower housing, past the now open Fresh Air intake door, I could see more insulation in the Fresh Air path.

How could a rat put it in there? The outside path for fresh air intake is through the vent holes in the cowl panel between windshield and hood - the holes are tiny! No way could a rat get in there!

I reached my hand way down and back in the blower housing, and could feel around down back in there, lots of junk. Went underneath, nothing to see, but felt around behind the wheel well on the passenger side, finally found more stuff. And something made of rubber. Realized I was feeling a large Duck Bill, that had one whole side eaten off, could reach right into a panel.

So... rain that goes into the cowl panel holes up top, drains out of the intake air path via a big rubber Duck Bill at the bottom, down low behind metal that is behind the wheel well. There should be one on the driver's side, too. The Duck Bill would normally be closed, except if the weight of water builds up on it, it opens some to let the water out.

But a rat can chew through the rubber Duck Bill, and crawl up into the whole cowl panel/air intake tract. It appears to have been stopped from getting into the cabin because the fresh air door was closed. If it could get by that door, then it could make it through the Recirc door opening, into the cabin.

So the rat was building a nest, and when I ran the Bronco in VENT, the suction of the blower started to pull all of the junk up in the Fresh Air inlet, into the blower wheel. The fins on the Nylon blower wheel, right at the outer edge (away from the motor plate), were melted a bit, every one of them. Won't hurt it's performance, but showed that shreds of foil-faced insulation had built up enough between the edge of the rotating blower wheel and the case, causing enough friction to melt the Nylon fins there.

It took a bit of work and compressed air to get the insulation out of the wheel. I pulled out the rest from the other places via vacuum and hand.

Now, what to do.
IF I could find a replacement Duck Bill, not sure I can, it might get eaten up, too. And the only way I can see to get to it is to pull the whole wheel well out, a lot of things are mounted onto or above the wheel well, like battery, Thermactor Air inlet and muffler, a bunch of wiring harnesses, etc. So I'm wondering if I should just fab a screen out of 1/4" hardware cloth to go over where the Duck Bill is. Will get some intake air from down low with that idea, but that is no worse than what it is doing now.

Stupid neighbor, smart rats, and a rat entry vulnerability point that most would never realize is there (I sure didn't!).

 

Now that its getting cold its time for cats to get in the engine compartments.

I bought a 79 bronco one time and it was a major project getting years of impacted compressed leaves out of the vents going down to the kick panels.

 

Pulling the ebrake from under the dash is easy. INSIDE... there is a 3/8 head and 1/2 nut that holds the ebrake to the bottom of the dash.
OUTSIDE..... remove the plastic wheel liner if equipped. Look on the firewall and you will see two 1/2 nuts. Remove them. Ebrake is loose and can be moved out of the way.
BACK INSIDE......the vent has 6 Phillips head screws.
I just did this, this past weekend. Easy job.
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