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Old Oct 23, 2021 | 01:32 PM
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Default HVAC Question

Hi ya'll - I have a 2002 and the other day I had the issue where the AC started coming out all of the vents (top, middle, and bottom) even though the setting was just on middle. I cycled through the settings and it did seem to change between them all and then when I got back to the middle setting all was OK again.

the next day I drove the car and the same issue happened but then it quickly went away and was ok after a short drive.

I did a lot of research on this issue on the forum and looks like it may be related to a vaccum leak. I poked around behind the intake manifold and underneath the battery and everything looks good to the extent that I was able to see.

the car previously did have the actuators replaced so I dont believe that could be the culprit.

Any idea why this issue seems to come and go? Is there anything else that I should look at?

Thank you for all of your help. it is appreciated
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Old Oct 23, 2021 | 05:53 PM
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You have a vacuum leak. There is a small vacuum line on the back of the intake manifold that supplies the cavuum needed for the mode actuators and depending on year a valve for the Air system.

This is disconnected when the intake manifold is removed and some techs have a hard time reconnecting it. It is also prone to damage from batteries that leak since it is routed under/behind the battery tray.
This line runs into the vacuum canister that is inside the passenger fender.
You can check to see if this is working properly at the vacuum fitting under the passenger side closeout panel in the foot well. There is a purple silicone hose that is connected to the Black plastic line coming from the vacuum canister. Disconnect this and put a vacuum gauge on the black line. If there is no vacuum then you have to trace that line for breaks. You may end up having to replace the line from the manifold to the vacuum canister. To replace the line the passenger fender will have to come off.

I have done this job many times. It is not that bad to do, just take your time. First step is to verify where the issue is.

Gary
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Old Oct 23, 2021 | 06:10 PM
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ok thank you very much that is what I was thinking. I remember seeing the black and purple hoses when I was checking the blower motor. I will go ahead and buy a vacauum pressure checker - what value should I be looking for from the black line? thank you again!
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