New clicking sound under dash, drivers side

From the diagram attached, it looks like "air outlet damper servo motor" is the likely name for your thingamajig. Or it could be the air mix control servo motor, not sure from the photo. To get to it for purposes of repair you will need to take apart the dash, which is covered in at least one place:
http://techno-fandom.org/~hobbit/cars/chris-dragon-dash.pdf

Probably a time consuming repair, although more fussy than difficult from the looks of it. It could be that the air damper is sticking for some reason, and the gears are grinding as a result. If the motor is damaged, you might be able to get a used one from the various Prius parts places, such as Prius hybrids sales and service Scottsburg Indiana

 

I am wondering whether the root cause of the problem is the motor binding up; or the AC amplifier control unit. I've also been noticing slight noises coming from the dash of my 2004 but have successfully ignored them, so far.

 

Here is what the servo circuits look like, being just a simple potentiometer for feedback. If the feedback is incorrect, the motor could continue to run when it shouldn't.

 

I cycled the fresh/recirculate and the defrost/dash vent motors, and the clicking sound went away. So I think the problem is a slightly dirty position sensing potentiometer located in one of the motors.

 

I also now have this problem. I've captured the sound and have an audio recording. I can't seem to upload a .wav or .mp3 file for posting and sharing. I'm new to PriusChat and could use some advice on uploading, if this an allowed file format option. The noise only occurs when the car (mine is a 2006 Prius) is on in both gas and battery modes. As soon as I turn it off, it stops. Any ideas?

 

I think you have to make 5 or more posts in order to be able to attach a file, as an anti-spam measure. The forum called "House of Pancakes" is for this purpose: Fred's House of Pancakes | PriusChat

Then try again to send your file.

 

Thank you!

I've successfully uploaded the audio file containing a sample of the clicking sound under the dash. It sounds like it is coming from the area just above the gas pedal.

Uploading tips - Under your preferences, says Browsing Preferences, in the Options section, there is a setting called Use the Flash-based uploader to upload attachments - this was checked by default, I deselected this and saved it. By doing this, when I would click Upload a File, it gave me a more specific file upload window. It specifically shows max file size of 5 MB and the accepted file types: zip, txt, pdf, png, jpg, jpeg, jpe, gif, xlsx

I had to zip my .wav file and the Upload worked.

 

It would help if you can identify the specific circumstances where the noise is present. For example:

- Does the clicking sound occur only when the cabin ventilation system is on? If yes, then the noise is related to a motor that moves the ventilation from dashboard to floor vents; or else the motor that enables and disables outside air vs. recirculation. Unless you are able to disassemble the instrument panel and look for that problem, you'll need to visit your local Toyota dealer for service.

- If the clicking sound is associated with your turning the steering wheel, then there is some interference between the plastic trim and the steering wheel shaft.

- Rapidly press the brake pedal and see if you hear the sound. If you do, then you are either hearing the brake actuator pump running, or there is an issue with the pedal mechanism itself, making the noise.

 

88 degrees outside, the car has been sitting (off) for about a couple of hours. Just went out and made sure that the vent and fan (no A/C) were the only functions running when I started it. Only put my foot on brake to start it. Turned off the fan all together. Vehicle is in Park, not moving, not using the steering wheel. The sound started within about 20 seconds. When driving, I have observed that it does continue. Pressing the brake pedal has no effect. Nothing I do seems to change the noise frequency or its occurrence, except turning off the car.

 

A mystery. If this bugs you, then I suggest you visit your local Toyota dealer and demonstrate the sound to the service writer.

 

I have the same problem of clicking and a slight whine on my 05 and have isolated it to the top fresh air door servo motor. When it makes the noise I can toggle the recirculate button and it will usually then swing all the way and fully seat the door on the second attempt then stop making the noise.

I am not sure if I can pull the blower assembly box and just clean and lubricate the pivot points the door swings on or if the fresh air door servo is too weak and needs to be replaced.

I see three screws holding the blower box assembly in place but I suspect it will be more of a pain than it looks to remove the air box.

 

As info.... I think I have the same noise that Susiel is experiencing:

It's somewhere just above the gas pedal and it's a clicking sound that happens often much like a relay going off / on constantly.
It happens while I am driving, idled at an intersection, or even parked when started in the morning or after I've been driving.

I will try to do Patrick's trick with the fresh/recirculate and defrost/front vents to see if this will alleviate the issue, otherwise, I will have to take it in for my scheduled (but slightly late) 165,000 mile service (with 10% off coupon) and have them check out the motors and such.

 

I have exactly the same problem in my 2008 Prius. I bought the car in 2010 (love it!) and it has always made a groaning noise when switching the outside air control between fresh and recirculate. I first noticed this new clicking noise last summer (in Australia) but it went away in winter and I had forgotten all about it until now in spring we are regularly getting warmer temperatures again. The noise sounds identical to that posted by Susiel, and it starts when the outside air temperature is above about 18 C (65 F) and the air control is set to outside (fresh) air. If I switch the air control to recirculate, the noise stops. Of course with my car being right hand drive, the noise comes from the front passenger side. I'd like to fix the issue as you'd think that the servo will sooner or later fail altogether, so I look forward to hearing if anyone has any luck getting this repaired! On a possibly related issue, does anyone else notice that the car always starts with the outside air control in recirculate when the weather is warmer? Mine has always done so, at the same temperature threshold as the new clicking noise - i.e. below about 18 C the air control will be where I left it when the car was switched off, above 18 C it will always be in recirculate when I start the car.

 

I have an issue with a clicking under my dash board driver side and it came out of no where while driving. I am a non aggressive driver and the second owner of the 2004 Prius, it only has a lil over 85,000 miles.

I posted the video of the sound. And the sound happens even if the car is parked or neutral.

 

I have a 2008 Prius that has the clicking noise as well but I can't pinpoint where it is coming from (either under the dash or engine). What is odd is that it stars clicking before I even start the car and continues on after it is started. Any ideas what this could be? Did this happen to you as well?

 

Hi there did you ever solved the problem? I have a 2009 prius and 2 months ago I noticed the exact same noise buy went away today it was doing it for about 10 min. On and off . What did you do in order to.fix it? Any info will be I appreciated