AC vents won't blow air

[hawkjm73]

Hi, all!

I've gotten into a fix. My dad was playing with the buttons on the climate screen, and now the air will only come from the outside dash vents, the round vents, and the windshield vents. I didn't see clearly, but I think it happened when he cycled the front defroster button on and then off. Now, whenever I press one of the airflow buttons, I can hear the air change like it diverting the flow, but air does not go anywhere else. I can have it set to floor only, and have air coming out of the afore mentioned vents only. I have tried everything I can think of to get the thing to work correctly again, to no avail. And yes, I have checked the little vent open/close sliders. They are fully open. Anybody have any idea how to get my AC back to normal?

[eagle33199]

are you sure defrost isn't still on? try just cycling those buttons on the steering wheel to see if it has any effect. also, use the A/C on/off button on the steering wheel to turn the whole system off and on again, see if that helps. a picture of the whole dash (from speedometer ovre to include MFD) with the climate screen pulled up would help us troubleshoot a little better.

IMO, it's either going to be something simple, and you'll smack your head and hide in a corner from shame , or it'll be something that really broke and you'll have to take it into the dealer. Either way, should be some fun!

[hawkjm73]

<div class='quotetop'>QUOTE(eagle33199 @ Oct 6 2006, 08:56 AM) [snapback]328858[/snapback]</div>

are you sure defrost isn't still on? try just cycling those buttons on the steering wheel to see if it has any effect. also, use the A/C on/off button on the steering wheel to turn the whole system off and on again, see if that helps. a picture of the whole dash (from speedometer ovre to include MFD) with the climate screen pulled up would help us troubleshoot a little better.
[/b]

Yeah, I've cycled the front defrost, the rear defrost, the AC, the fan, the recirculation, and the auto function from the screen and from the wheel (where applicable). The yellow bars over the defrosts will turn on and off (they are off at the moment). I didn't wait to see if they did anything as it's way to hot for them to be on. The bar over the AC cycles, and I can feel the temperature difference when it is off. The auto and the recirculation icons cycle correctly on the screen and by the speedometer. The fan will shut off and change speeds, by my command or according to the computer when set to auto. It will simply not change the vents. By the way, this is an '05 with nav and I'm in Phoenix, so you can probably guess why I really want all the vents to blow cold air again. I'll go see if I can get a decent picture.

IMO, it's either going to be something simple, and you'll smack your head and hide in a corner from shame , or it'll be something that really broke and you'll have to take it into the dealer. Either way, should be some fun!
[/b]

Ugh, I'm really hoping for the first option. I have no problem hiding in a corner for a while, but trying to get a dealer to troubleshoot this sounds like a hole-in-the-pocket just waiting to happen.

[eagle33199]

<div class='quotetop'>QUOTE(hawkjm73 @ Oct 6 2006, 12:32 PM) [snapback]329010[/snapback]</div>

Ugh, I'm really hoping for the first option. I have no problem hiding in a corner for a while, but trying to get a dealer to troubleshoot this sounds like a hole-in-the-pocket just waiting to happen.
[/b]

With the car being an '05, i would think a problem like this would fall under warrenty. We'll see if tahts needed when you get that picture for us.

[Rick Grahn]

Weird problem. I'v never heard of any car (let alone a Prius) with this type of problem. Could Dad have accidentally found a mechanics override/testing function through a series of screen touches?

[hawkjm73]

<div class='quotetop'>QUOTE(eagle33199 @ Oct 6 2006, 02:12 PM) [snapback]329043[/snapback]</div>

With the car being an '05, i would think a problem like this would fall under warrenty. We'll see if tahts needed when you get that picture for us.
[/b]

I wish. I drive a LOT and am already past the 36k mark and, probably unwisely, didn't get an extended warranty.


<div class='quotetop'>QUOTE(Rick Grahn @ Oct 6 2006, 05:03 PM) [snapback]329159[/snapback]</div>

Weird problem. I'v never heard of any car (let alone a Prius) with this type of problem. Could Dad have accidentally found a mechanics override/testing function through a series of screen touches?
[/b]

Well, unless it was something really hidden, no. I was able to see it was on the climate screen both before and after it stopped working right. None of the servece menus activated. I just didn't see exactly which button was pressed at the exact moment. I suppose there could be some sort of testing function, but if so, there were no visual or audio clues that it had been activated.

[IsrAmeriPrius]

My semi-educated guess is that the problem is not due to faulty controls.

Most car air conditioning systems control the air flow to the different vents by opening and closing duct doors which are operated by either vacuum servo units or electrical motors. I do not know which it is in the Prius. I had a similar problem in my old Mercedes, where the cause was a vacuum leak and cracked diaphragms. They had to dismantle the entire dash to replace the faulty parts and install new vacuum lines. In a system using electric motors, blown fuses, loose connections or shorts can be the cause.

Sometimes, objects can fall down defroster vents and block a door from moving.

[hawkjm73]

Okay, here are a couple of pics. In the first, the fan is on, and the vents are set to face only, but you can see the dash mat lifted under the windshield showing airflow there. The second picture had the fan off so you can see the dashmat sitting normally under the windshield.


[attachmentid=5216]

[attachmentid=5217]

[Beryl Octet]

<div class='quotetop'>QUOTE(IsrAmeriPrius @ Oct 6 2006, 08:32 PM) [snapback]329227[/snapback]</div>

My semi-educated guess is that the problem is not due to faulty controls.

Most car air conditioning systems control the air flow to the different vents by opening and closing duct doors which are operated by either vacuum servo units or electrical motors. I do not know which it is in the Prius. I had a similar problem in my old Mercedes, where the cause was a vacuum leak and cracked diaphragms. They had to dismantle the entire dash to replace the faulty parts and install new vacuum lines. In a system using electric motors, blown fuses, loose connections or shorts can be the cause.

Sometimes, objects can fall down defroster vents and block a door from moving.
[/b]

I had a simlar problem with a VW Golf. The vacuum servo must have been the first part of the car, and then everything else assembled around it... Interestingly, when it failed, it failed in such a manner that defroster air was still blowing. When I ordered the parts, the counter guy explained that it was designed that if the servo failed, defrost is the "default". I suspect something is broken, but it might be worth popping off the glove compartment and the cabin air filter, and see if you have a UFO in there or something before taking it in to your dealer.

[hawkjm73]

<div class='quotetop'>QUOTE(Beryl Octet @ Oct 7 2006, 04:59 PM) [snapback]329513[/snapback]</div>

I had a simlar problem with a VW Golf. The vacuum servo must have been the first part of the car, and then everything else assembled around it... Interestingly, when it failed, it failed in such a manner that defroster air was still blowing. When I ordered the parts, the counter guy explained that it was designed that if the servo failed, defrost is the "default". I suspect something is broken, but it might be worth popping off the glove compartment and the cabin air filter, and see if you have a UFO in there or something before taking it in to your dealer.
[/b]

I have no problem taking the whole dash apart myself if its likely to be a servo. Anybody got an idea where I should look for whatever controls the airflow? Or, just point me to the section of the tech manual that covers it. That pile of files is such a disaster, I could look for days and never see what I need.

Failing to "defrost" makes sense. It's the setting that, should it be unavailable, could cause a hazard.