CosmoRx

AC has been working great and all of a sudden when you go to start the car the AC never really comes on. The blower runs low speed and does not respond to any changes made. The air blows at ambient temperature. Another curious observation is the dummy key will not release when this happens. I see no errors on the dashboard, have reset all settings on the car. Any ideas?

Edit: A note, the ac fan blower when this issue is happening doesnt turn off when you turn the key off, and randomly will turn on if you have the door open. Its almost like a weird electrical gremlin. Ive debated disconnecting battery to do a pcm reset to see if that will help.

Maxant13

Same issue just started happening in my wife's 2012 cayenne. I'll be taking it in to the shop soon and let you know what they find.

gadgetrex

This sounds a lot like a problem I had with my 2012 CTT. The AC stopped working properly and it turned out to be corrosion of wires around the passenger footwell from a block drain plug. After they fixed the blower + wires, they had to recharge the AC system. Good luck.

CosmoRx

You are right on Gadgetrex! My wife just said that the last couple times this happened it was right after she washed the car. Just noticed the passenger side floormat is wet. Time to go figure out where they drains are on that side of the car. Thanks man!!

deilenberger

Unfortunately - if it's causing problems - there is already corrosion in that wiring bundle that will continue causing problems.

There are some longish threads on cleaning out the various drains that can plug up and cause this flooding. Mostly you've got to remove the wheel on that side, then pull back or remove the wheel liner and look for little rubber tube like things that hang down or come out of the firewall.

The fix for the cowl drains (the ones that will let water in if you go through the carswash) is to remove them, and try to get all the stuff (leaves, crud, etc) that is backed up behind them to flow down out of the hole.

The AC drain can be removed from inside the car and cleaned out. It's a PITA, but very DIY sort of thing. Most people cut the flapper valve off the end of the drain when they do this (that's an official Porsche modification actually..)

Start here: https://rennlist.com/forums/cayenne-...n-out-diy.html

Then go here: https://rennlist.com/forums/cayenne-...carpet-up.html

And I'd suggest getting under the carpet to take out the quart or so of water that is trapped in the 2" of foam rubber under the carpeting.

BTW - if the right side cowl drains are plugged up - chances are excellent the left side ones are too.. you just haven't noticed it yet - and there is a wiring harness that runs through that area also.

North Shore 911

Possibly a related issue, but I'm looking for your guys' thoughts on this: The ventilated cooling in both front seats of my 2012 Cayenne S really aren't working well. They seem to blow limited amounts of air, and it is not particularly cold (even on the coldest setting). My main A/C is working fine, it's just the seats that are underwhelming.

So my question is: Is there any chance that this is the same issue?

I'm hoping that there are other gremlins lurking under my seats that a trip to the Dealer for some CPO work will solve, but either way, I'll be cleaning out my drain lines based on what I'm reading in these threads

deilenberger

I have been told that the seat's suck.. ie - the fan draws air through the holes. I think the person telling me that was wrong (have to test it sometime..) The rear footwell AC vents end up under the seat around where the fan would draw from if the fan is blowing out the holes. You might try taking the cooling system off auto - and turn on the chest level vents and the foot vents and see if that makes a difference. If you have the 4 zone system, and no one in the back seat, setting it to blow only from the footwell vents might help too..

gadgetrex

CosmoRX - I am sorry to have called it on this one. It is ridiculous that plugged drains cause leaks into the vehicle and attendant damage. My situation sounds much like yours - I started noticing water in the passenger footwell after leaving the car wash. I wasn't too worried, as I use OEM rubber mats and figured that they would catch the water. Apparently, the water (or some significant portion thereof) chose to ignore the mats.

CosmoRx

I removed the rubber drain ends, cleared out a TON of leaves. After letting it dry overnight ive had ZERO issues. No more water coming in via carwash etc.

r553

I removed my rubber cowl drain flaps and cut off the AC drain flapper to try and avoid problems.

Kozak17

same thing , after I take it to the wash, the front passenger side is wet on the floor. Will trying to clean out like the guys recommended.
my ac started acting up, I can put the blower in any position and it will go from low to high randomly and blow hot air.