Rockit

My A/C works great...all my vent controls work great.

I never needed the heat until now and I just got the car. The temperature control on the heat side blows cool air unless the last click to hot max and I get full hot air and then the heat works fine but is full hot.

During the restoration and replacing worn parts I've replaced that would contribute to this symptom:
Rear blower motor resistor and temp sensor
Cleaned temp sensor in CCU
Replaced the CCU fan motor
New heat door flap diaphragm.

I was told by a friend maybe the blend door motors in the foot wells are not working...I don't have a scanner to check the flaps but both not working at once?

The only other solution is send the CCU out for repair or upgrade to these guys http://www.ecudoctors.com/porsche-ec...trol-unit.html $1,000

Did anyone else have a similar problem they found a fix. I did go to BergvillFX site too.

Rockit

I'm going to pull the foot well carpets and check if the foot well servo's move with the temp ****. If so the CCU is bad...if not both servo's are bad.

993/907

Rockit.....it's quite easy to access the blend doors in each footwell for a visual check of their operation.
It's possible that one failed first, then the 2nd failed sometime later...you wouldn't have known either/both failed since you were not calling for heat?

Gordo

Rockit

Thanks we both posted at the same time. I will check that next...

ToreB

The CCU will stop any attempts to move a failing servo until next time it starts up.
A tip would be to reset the CCU before you do the mixer servo inspection. This can be done by keeping the ignition off until the CCU fan stops, (up to 20 minutes) or to disconnect the battery power supply for some seconds.
It is not uncommon to have two mixer servos failing, you probably have had problems for a long time, but haven't noticed it. There is probably no need for costly CCU repairs.
Cheers,
Tore

pp000830

There is a rebuilder who replaces the guts to the mixing servomotors or they can just ship you a kit containing all the guts as the servomotors are not really serviceable otherwise. The kits are between $160 and a little over $200 dollars and is located in Germany.

https://rennlist.com/forums/993-foru...ere-we-go.html

http://www.partisan-autoteile.de/epa...ellmotoren_993

Observing the function of the servo controlled heat mixing valves in the footwells is easy to do. Also there are three under the cover behind the cowl in the trunk you can look at. They suffer the same failure mode. I have replaced the top center one (fresh air servo) that gets a lot of cycling.

Rockit

Lots of good stuff Thank You...

Could you tell me what the part numbers are of the footwell Motors?
I found 993 624 325 00 in the manual but it lists only one? I'm not sure I got the right motor.

I cant read German and don't know if they understand English, while that's a great solution. I have a parts source I can get about 30-35% off list for OEM $239 each and for about $250 more I can get new motors faster and just plug and play.

pp000830

If you look a little to the left of the part number there should be a little L/R or a quantity of 2 if both sides use the same part number. I see no reason why they are not the same. This is why there may only be one part number listed.

Rockit

Thank You!!

pp000830

I looked in the catalog, same servo part both sides.

Rockit

I must have an old book. It shows both side hoses & clamps and mixer boxes but it shows just one motor...no L/R

Just ordered two new servo's ouch! But will have them Friday.

Alan thanks so much for your time, very much appreciate it!!!

mpruden

It's a little late given that you've already ordered, but I can confirm that Michael at PARTisan can read and write in English.

To place my order, I just found his email address on the website then sent him an email in English requesting 2 mixer servo kits. He responded with an invoice in English. Payment was through paypal making for a very simple transaction.

Hope this helps the next person that stumbles across this thread.

pp000830

Yes ordering is very easy.

ble2011

Mines done this since I've gotten it. I've just told my wife that its just a switch. You got hot air or cold air. Which would you prefer?

pp000830

A common situation where ones wife is always trying to get warm or cold.