darrinsmith

Ok I finally fixed the stupid air cond servo motors. I ordered 3 (defroster flap, left hand outboard, and right hand temperature mixer flap) - My car is a RHD ($280 each OUCH).
I didn't bother with the footwell servos as it never get's really cold here.
 
You need to remove the dash, it's a pain but can be done. The trick is to work slowly. The procedure is covered in the workshop manual, it just looks much harder than it is.
Some points to note.
1) I'd suggest unlocking the steering wheel, and putting the car into "D" and opening the rear tailgate BEFORE you disconnect the battery (you will need to remove the passenger and driver's air bags so you MUST disconnect the battery-also note DON'T close the tailgate with the battery removed, you can't open it again!). This is mentioned in the workshop manual under the section on removing the driver's airbag.
2) You WILL need to remove the steering wheel as the lower dash bar won't clear it and will break (ask me how I know!, however it can be easily fixed once the car is disassembled if you need).
3) Putting the shifter into "D" will allow easy removal of the ash tray, A/C controller and ultimately the dash carrier unit. Put a thick sock over the shifter so you don't scratch it.
4) When removing the THOUSANDS of plastic trim clips, use 2 spatulas one on each side of the clip otherwise they just break off. I destroyed more than half of mine, but it still all went back together just fine.
5) Take note of the location of the middle BOSE speaker wire, it has a very tricky routing, the other speaker wires etc are fairly straight forward.
 
Now on RHD cars the right hand servo's are boxed in by the foot brake mechanism and holder (not a problem in LHD cars).
see http://www.specialistvehiclepreparations.com/blog/porsche-cayenne-heater-flap-replacement
 
I pondered this for a while as the above article says you have to remove the dash bar (which is basically impossible-I tried for about an hour to figure it out, but I couldn't budge it).
However you can save yourself a LOT of hassle by simply removing the foot brake mechanism!
It's actually very easy - again the procedure is in the workshop manual.
1) remove the metal "shield" from the top of the assembly (1 bolt and wiggle the shield up and through the wiring)
2) remove the brake light switch (one little bolt).
3) remove the 2 M8 bolts from the assembly (Not the big black on in the middle).
4) remove the pedal gas strut - good time to replace it..
5) wiggle the assembly up and out of the hanger. - I basically just hangs there on a hook setup, you may need to give it a little "tap" with a hammer to remove and also to re-seat it on re-assembly.
There is NO need to unclip the brake cable or the release cable, there's enough slack to simple push the assembly out of the way.
 
You can then get to those pesky servo motors quite easily using the tool similar to the one in this thread...
http://www.clubtouareg.com/forums/f73/hvac-flap-motor-replacement-dash-removal-185361.html
 
Note that Durametric CANNOT place the servo motors into service position (if they're broken then they won't move anyhow) so when you replace the motors, make sure the little arms engage with the white plastic flap arms.
Also check the flaps move freely before fitting the new motors, for good measure lubricate the arm pins with Porsche "liquid gold" or any other white lubricant.
 
The whole job took me about 5 hours to disassemble, 3 hours to replace the motors (most of that was actually trying to work out how to do it), and about 4 hours to put it all back together.
I could do it in half the time easily now, but hopefully I'll never have to do it again.
Cheers from Perth!
DS