I've got this really odd problem with my 03 4runner. When I start it up (every time!!), as soon as my a/c starts blowing, I get this buzzing sound that stops immediately after I turn off the "inside air" button. The sound seems to be coming from inside the dash...almost sounds like its coming from behind the glove box. Any ideas what could be causing this sound? It doesn't affect the way my a/c works...still blows air and blows cold...just makes that annoying sound!!

I've got a video that shows the sequence of events (start the car, buzzing sound, turn off the "inside air", buzzing stops) but I can't figure out how to post it here.

My friend has this exact same issue in his 4th gen. IIRC, it was from either the compressor or the condenser for the A/C which is located behind the glovebox. Not 100% on that, but something's telling me that's what it was....

I was able to post the video on YouTube...maybe this will help.

IMG 0053 - YouTube

Anyone else have any ideas on this noise I keep having? Thanks in advance for any help.

Did you try removing the glove box and seeing what it causing that sound?

When you turn off the "recycle air" switch, the only difference should be taking air from the inside the car and that air intake is usually below the glovebox. I would check to see if you have a piece of paper or something stuck in the intake.

Thanks for your reply. I'm hoping to have time to do that this evening or some evening this week since I'll have some time off b/c of Thanksgiving.

***Disclaimer: I am not very mechanically inclined due to being a life long computer geek...but I ain't scared to try***

With that being said, how difficult is it to take off the glovebox? What should I be looking for once I take it off...I don't know what the air intake will look like. Is it just some sort of vent?

OK...my wife says that the sound never completely goes away. It comes back at random intervals even when the "recycle air" is turned off. It does kinda sound like there may be a leaf or something in the system that is making that sound.

So since I'm a computer geek and not a mechanic, I started searching for a YouTube video to give me step by step instructions on how to take out the glove box...looks pretty easy so I'll try that this evening. But I also found another video that shows how to change the cabin air filter, which I'm guessing is what filters any outside air coming into the cabin right? (yes, I'm pretty sharp) So if there were leaves or some other kind of debris stuck in the cabin air filter, would the symptoms I'm having point to that being the cause of the problem?

Again, thanks for any help...and thanks for being patient with a guy who is "mechanically challenged."

no problem, yes, check the cabin air filter, very easy to remove. i think there must be leaves or something, especially this time of year.

computer geek, eh? Funny you should say that cause I am a computer support tech, but I do like to get my hands dirty and work on cars, or at least do minor stuff repairs/maintenance.

Yeah, I've been in the computer field since I was in the Navy...roughly 20 years now...damn I'm getting old...

Ok...checked the cabin air filter and it was pretty clean...vacuumed it of for good measure. Long story short, I still have the same sound when the recycle air is on. I took out the little compartment above the glove box so I could have a better view of that area. I found out that when you turn on the "recycle air" button, there is a small hood that tilts towards the back and then the sound starts. When I turn "recycle air" button off, the small hood tilts forward and the sound stops. I also felt all around this "thing" (if someone could tell me what the hell the proper name is for this, I'll stop calling it a "thing") to see if I could tell where the sound was coming from based off of the vibrations but I can't seem to pinpoint where it's coming from. I'm hoping that I don't have to replace this whole "thing" bc I'm sure it's expensive and I will probably have to pull the dash to get it out...probably past my skill level without step by step instructions.

For your viewing pleasure (and hopefully so someone can help me figure out where this sound is coming from), I've posted another video of the problem. I'm videoing the cabin air filter "thing" that is inside the dash and right behind the glove box.

IMG 0054 - YouTube

I'm no expert but I have a 03 4runner and I was told to check my blend door... It could have something loose and rattling around in there. It controls the amount of air that will be released to each side (aka your climate control)

Where is the blend door? And how do I access it to see if there is anything rattling around in it? And if it was the blend door, would it only make the noise when the "recycle air" is on? Seems like it'd do it all the time right?

It requires taking off the whole dash is all I know. This is just what an a couple auto shops have told me they wanted to check when I had issues with it but it went away so I havent had it officially checked. Mine didnt make the noise like yours though... Just a quiet whistle. And yeah, like I said I am not an expert, just trying to get creative juices flowing in other people to help out.

check out this post

Thanks for the idea. I'm pretty sure it's coming from the "thing" that I videoed bc I can feel it vibrate when the noise starts. Is the blend door in that same area? Any other ideas?

Can anyone tell me the proper name for the white assembly with the moving hood in my video? If I know what the proper name is, I can probably put my google skills to work and do some more searching to try to find my noise. Or at a very minimum, find out how much it'd cost to replace it. Thanks in advance.

Want to bump this back to the top to see if anyone has any other ideas...or maybe can tell me what the assembly where the noise is coming from is called. Thanks.