No wonder blower motor was making a sound and not blowing well. Nasty! And just where do they get in to do this?
I vacuumed out as much as vacuum would reach. Probably more in there somewhere.

 

I had that happen to me too! Except it was with nut shells! i was wondering why my blower motor would not work at all...then I took it out (it was sorta difficult) and was scooping out the shells by the handfull! Luckily on our car's HVAC, the evaporator blocks the blower motor area. So the little varmint didn't get into the interior (thank you Lord!).

To answer your question, I think they get in the little metal screen that is on the "rain tray" just under the windshield. Mine has these plastic clips that kinda hold it in, and they tend to get loose all the time.

 

There's a LARGE drain for rain water on either side of the cowl under the fenders. Mice can crawl right in without even ducking their heads.

 

Huh...really? I'm not sure where this is. Do you know of a picture?


These HVAC screens are what I noticed were loose on mine and I suspect can be a problem.

 

Those are the entrance for fresh air into the cowl, RM. They go into an area that could be thought of as a cross-car tunnel. Inside that tunnel is your wiper linkage, and an intake for fresh air into the HVAC system. When it rains, run-off from the windshield and other places runs into this tunnel. So that it's not trapped, on the floor of the tunnel, at the end of the tunnel on both the driver and passenger side is a small mouth like opening. This lets the rain run out, exiting behind the fender. Otherwise, rain would build up, overcome the lip around that fresh air intake, and you have rain water flooding into your HVAC box.

It's this mouth, draining behind the fender, at the ends of the cowl, that Drew is referencing.

So that leaves and other debris don't clog these drains, they are deliberately large, and unobstructed. You could throw screen over them, but they would quickly clog up.

FYI...I had a '95 Neon. Very early build, from late '94. They used a good sized rubber tube to control where that rain run-off was directed, as it exited that mouth at the side of the cowl. Some bean counter, to save money, had engineering remove the drain on the driver side. There was only one on the passenger side. Sitting in my driveway, the rain would run down the windshield (large for a small car due to cab-forward design) and collect in the bottom of the cowl. What could get to the drain tube ran out. But the bottoms of these cowls (all cowls) is not smooth as glass. It has shapes, bumps, pockets, and irregularities. Water collects in the low spots when parked. Then you drive. On my first left hand turn each morning after a rain, you would hear a wave of water rush across the cowl to the passenger side, hit the lip of the fresh air intake, overwhelm it, fall into the HVAC box, where you would hear it hit the running blower motor/squirrel cage. Within a year, the bearings in the blower motor were shot and squealing, do to rust. The fix? A bulletin about 5 pages long, new blower motor, a drill bit, a tube of urethane sealer, a driver side drain tube, and a revised cowl trim with a lip seal to direct rain water off to the sides instead of letting it roll into the cowl.

 

Its behind the fenders, sorta forward of & between the hinges.Hard to take a pic of.There is suppose to be a rubber flap covering the "hole".It opens when something pushes out from inside the cowl, not so much the other way, but they can fall off over time.

 

There's a rubber flap on the passenger's side. The driver's side is wide open. Two 1" diameter (minimum) holes.

 

Ohhh..Okay. I see now I think. I know theres a rubber grommet on the passenger side fender where the antenna goes into the side firewall. I think possibly the wire harness goes around to that side as well because the ECM is right there too.

 

I guess I could take the camera out to the driveway to get a better pic, but yeah, sorta...

The huge triangular hole by the antenna grommet is the cowl plenum drain on the passenger's side. The rubber flap snaps in the little oval holes and allows water to run out. The large square hole below is where the engine harness enters the car.

These pics aren't the best, because I was documenting my work, not the drain holes. In this case the car was well into disassembly, so things like the rubber flap were already removed, cleaned, tagged and bagged for reassembly.



Mice are messy, but the primary reason the pictured car is torn down, is to strip and replace the seam sealer that has dried up and started cracking. Water runs in the joints under the sealer, and it starts to rust. Cleaning all the drain paths helps, but all the seam sealers on thirdgens are past their expected lifetimes.

 

Oh there we go! Now that looks familiar!

Question, for that water shield, how is it attached to the firewall? Is it glued in on the top there?

 

One of my guys pulled a (recently) decapitated rat out of blower a while back. It was pretty squishy and foul.

GD

 

So restarting this old thread. Same issue with my fresh air cowl. I have a 1" hole inside the bulk head which is letting water into the cabin behind the dash. I dug out tons of mouse nest and filth!. Has anyone converted the vent not to allow water in? Im not bothered about fresh air as I always drive around with the roof off but it sounds like the air comes in else where. I want to stop water getting in so want to fabricate a metal cover under the cowl to stop everything and seal it up tight!! Your views anyone?