Help: Corolla/Prizm AC/Heater noise

I would geuss that something has gotten into the fan, either leaves or something falling into it, or something decided to make it's 'home' there. You'll have to remove it, on the passenger's side of the car by removing three 10mm bolts and lowering the 'squirrel cage' from it's housing.

This is a Best Guess, by the way; it may be something else further up in the system blockin airflow. On the 'front side', ie, the dasboard vents, it's a blower, but on the 'backside' ie the vents that bring fresh air into the car, it acts like a vacuum cleaner.

That sounds like rodents got in there. I have had it happen to me a number of times. I now keep a "sticky" trap baited with peanut butter in the passenger side floor. On Christmas day I found a large mouse stuck on the trap.

---MIKE---

Access to the fan (sometimes referred to as a "squirrel cage") is from underneath the passenger side of the dashboard.

Should be able to get to it from under the dash.

If you've been running the fan alot, the poor thing is probably beat-up senseless. But I'd still wear some nice, thick gloves before pulling the last bolt and dropping the cage!

They love getting in there. When I bought my Mazda from my drummer last month, we couldn't find the key. He said, look in the glove box. There was a big, fluffy 'ball' of insulation in there. I started to stick my hand into it, and a little face popped out on the other side of it, and ZOOOM! The little thing made a bee-line for the door.

The tires were so bad I had it towed home, and in the process of checking it out and cleaning it, I fired up the fan. What a racket!! No rodents, but there sure were a lot of acorns and the entire fan cage was stuffed with insulation!

LOL! Reminds me of a road test one of the female DSM's took with a customer and service manager to determine the cause of a strange noise in the fan and randomly in other parts of the car. The service manager is driving, the female customer is in the front passenger seat, and the DSM is in the back seat. The service manager looked in the rear view mirror at a stop sign, sees a mouse sitting on the back shelf, and tells the customer and DSM that if they turn around they would see the source of the noise. They turn around, scream simultaneously, and bail out and refuse to get back into the car so the service manager drove back to the shop without them and sent someone back to go get them.

so funny stories, thanks guys i feel better now. I actually have accessed the cage today, I can not open it, bolt too tight, so I cut the cage grill (plasitic) and pull out lots of leafs and batting!!! the batting (someting flocculent) is yellow and looks like cigarette butt tissue, now I am not sure it is a nest made by some small animals or a carious filter? could you tell me?

the fan blower inside/under the cage is supposed to be empty or with a filter?

Thanks a lot!

Yeah, that's it! They take it from under the hood, or, usually, from behind the flooring at the firewall and carry it into the cage where they make a nice little nest of the stuff. Same stuff that was in the Mazda's glovebox and fan.

I'm not sure if there was a filter in '99. If there is, there will be a removable panel in the glovebox and the filter will be behind that.

Hey, you're welcome! Happy (warm!) motoring!

That is definitely a nest made by a small animal. The yellow material could come from padding underneath the carpeting, from a sound insulator under the hood, from padding underneath the dashboard, from padding underneath the seats, and from somewhere else altogether, like house insuslation.

The inside of the blower cage should be empty - no filters in the circular cage.

Thanks all you guys!

You're welcome!