jtilden

Greetings fellow Rennlisters! I have searched the forums, but cannot find a definitive answer to my problem. The a/c blows cold....but only on the drivers side. the passenger side servo was bad and has been replaced. I do get a fault light and the durametric indicates a bad rear blower motor. So my question is this...what blower motor is it pointing out?...since there is strong pressure coming from the driver side i am assuming that the blower on the left side of the engine bay is doing it's job. Is there another secondary blower buried underneath somewhere? As always, thanks in advance for your replies.

budge96

There are two inside the evap/expansion valve condensing unit under the cowl,if the passenger side
is getting no volume it could be the fan motor or mixing flap...Bert

ToreB

The rear/aux fan is placed in the left side of the engine compartment. It's only involved when you need heated air. Most air flow problems with differences between dash sides are caused by inert or dead mixer servos. But these mostly cause problems when you have set the temp **** to heat.
You are describing having problems with air flow when you need cold air, does that mean that you have set the temperature to minimum? If not, the above is probably the culprit. What fault light is lit?
Have a look here for details:
www.porschehvac.bergvill.com
Cheers,
Tore

ble2011

Are your right and left blower HVAC fans functioning correctly in the back of the trunk area? These feed the vents and if one is not working correctly, the pressure in the right or left vent will be minimal if at all.

jtilden

the temperature has been set to minimum, I will dive into the servos when i get home tonight. Thanks

Thanks...I will check them out tonight

jtilden

I had a chance to look at the car this weekend, this is what i did:
1) Checked to make sure the servos/flaps beneath the dash were working.
2) Took the cover off the cabin filter to make sure the passenger fan was blowing.
3) Cycled the temp between max and minimum, observed the flaps in the wheel well doing their job as well as the rear blower coming on.
4) With nothing else selected (ac off, heat on min) I turned the fan **** from min to max, verified that air is strong on drivers side and weak on passenger side
5) Checked the relays for bad connections
in every instance the passenger side air was very low compared to the driver side. Even the center vent passenger side was weak compared to the center driver side. I was attempting this by myself so I could not see what was happening in the trunk area. I am going to assume that one of the servos is bad causing the right side not to open....but which one? The defrost or the fresh air.

993/907

[QUOTE=jtilden;9762543]I had a chance to look at the car this weekend, this is
observed the flaps in the wheel well doing their job as well as the rear blower coming on.

Do you mean flap (servo) in the passenger foot well?
If not, check it out...they are prone to failure.

Gordo

jtilden

[quote=993/907;9762856]Yes the flaps (servo) in the passenger foot well are good

ToreB

You might have a defective Defrost/center nozzle servo. It's placed in the trunk along with the others, have a friend to turn ***** and press buttons and look for faults. How to os described in my previous mentioned web page.
A one-man alternative is to connect an OBD tool and look for fault codes in the CCU.
Cheers,
Tore

jtilden

finally decided to hook up the durametric and this is what i got:
31, Left mixing flap motor
45, inside sensor motor
43, rear blower motor stage 1
46, rear blower motor stage 1

The one that baffles me is the left mixing flap motor, both servos and flaps in the passenger wheel wells do their job (open when temp is max, close when temp is set to min). Unless that is the wrong mixing flap that i am looking at. The second one, inside sensor motor is probably what is causing my center and passenger vent to not blow air. I am going to concentrate my efforts on the first 2 for now since we have been in the 100's degree temps here in TX and the rear blower is used when the heat is needed.

jtilden

jtilden

All of the servos in the trunk initialize when they are supposed to...or i should say they "appear" to initialize....all three shift from one position to another is more accurate, whether that's right or not is the question

atcbi5

Move the temp control to heat. Hot air should blow thru both vents. If so, then I am affrid the control unit is bad

jtilden

are you saying that hot air should blow thru both at the same intensity? or do you mean hot air thru both sides with right being weak and left still being strongest? If so, heat blows thru both sides with the same results....passenger side weak, drivers side strong current

jtilden

what i don't understand is how the right side is weaker than the left...when you look down the center vent it appears to be one opening supplying both vents