titi20072009

Dear all,
I have some issues with the temperature inside my 993.
the CCU seems to work (blowing speed)...
but the air blowing by the fan is very hot inside the car (whatever the temperature indicate by the CCU).
If the fan are closing, there is still some hot air blowing (very limited but very hot).
I have only some AC air on the left fan ventilation (the 3 others ones blows only hot).
Did you have any suggestions?

Dplus

Hopefully this helps: Heater Always On - Page 2 - Rennlist - Porsche Discussion Forums

ToreB

You probably have one or two worn-out mixer servo motors. See here how to test them:
https://www.bergvillfx.com/categorie...test-procedure
Cheers,
Tore

NeinNeinThree

My mixer servo was on on the pass side kick panel area, quick fix is to shut it and disconnect it until you buy one.

titi20072009

many thanks to all of you for helping me.
To complete the description of my problem, sometimes (not every time), there is some smoke inside the car with an horrible smell of burning plastic...

titi20072009

Thanks Tore.
They seems to works together (there is some noise when I change the speed of blowing 0/1/2/3/4 for example) but due to difficulty to access I didn't "see" them working.
Do you think if I disconnect it, it will stop the hot air in the car?
Is the diagnostic software Porsche (or other) is able to determinate at 100% the problem?

ToreB

If you want to fix your issue, you have to change any faulty components. The first step is to find the fault. Accessing the mixer servos is not difficult, it is a matter of removing the carpet walls. Using a OBD tool will help you.
Since your initial fault description is constant heated air, one or both mixer servo valves are probably already stuck in the open position. Disconnecting a servo motor will stop any motion.
T

pp000830

Hi Titi,
We are so lucky to have Tore in our group.
The heating duct butterfly valve servos can be expensive to buy new.
They can be rebuilt by:
http://www.partisan-autoteile.de/Spa...ts-for-964/993
If you live in Europe.
In the US one can email Partisan and request a rebuild kit not listed on their website to avoid the time and expense of shipping your servos to them and back.
Removing the servos is easy and only requires a Phillips screwdriver to remove the carpeted covers and the servos behind them. Rebuilding the servos is a kitchen table DIY effort and not too difficult:
https://993servicerepair.blogspot.co...ning-hvac.html
Good luck with sorting this out.
Andy