Climate Control Air Temp incorrect hot or cold
01-05-2005, 01:43 PM
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Climate Control Air Temp incorrect hot or cold
Hi all. After getting my 993 last week I immediately noticed that the air coming from the center and right vents was always hot regardless of what the temperature dial was set to. The left side vent worked fine providing the proper temperature air. Air was always sent to the proper location (defrost, dash vents or floor). Only the temperature was incorrect at the center and right side of the car. So......search the forums I did. I found all the info I needed to sort the problem out but what I didn't find was any pictures of the heater valves in the footwells that were the cause of my problem. I decided to take some for the benefit of anyone else that has the problem of incorrect air temp when air is flowing to the correct vents.
Warm air supply is sent forward from the engine compartment to the passenger compartment on both sides of the car. The warm air flow is controlled by the temp dial on the dash which adjusts the heater valves located behind the kick panels in the footwells (see picture #1) The heater valve assembly is the black plastic piece between the pink and tan hoses in the picture.
If the motor that actuates this valve (see picture #2) fails the valve becomes stuck in whatever position it was in when the motor failed resulting in too hot or too cold air on the respective side of the car.
The third picture is of the heater valve removed with the motor detached.
For the sake of completeness here is the url of a uk site mentioned in this forum previously which has some great instructions on repair these valve motors:
http://www.porsche964.co.uk/technical/servos.htm
Mine could not be repaired since the circuit board and spring contacts were burned. I guess I'll have to pony up the $140 for a new motor.
Cheers! :thumbup
Warm air supply is sent forward from the engine compartment to the passenger compartment on both sides of the car. The warm air flow is controlled by the temp dial on the dash which adjusts the heater valves located behind the kick panels in the footwells (see picture #1) The heater valve assembly is the black plastic piece between the pink and tan hoses in the picture.
If the motor that actuates this valve (see picture #2) fails the valve becomes stuck in whatever position it was in when the motor failed resulting in too hot or too cold air on the respective side of the car.
The third picture is of the heater valve removed with the motor detached.
For the sake of completeness here is the url of a uk site mentioned in this forum previously which has some great instructions on repair these valve motors:
http://www.porsche964.co.uk/technical/servos.htm
Mine could not be repaired since the circuit board and spring contacts were burned. I guess I'll have to pony up the $140 for a new motor.
Cheers! :thumbup
01-05-2005, 02:27 PM
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Scott,
Great pictures. I just fixed a similar problem recently and took some pics, but haven't posted them yet. My problem was not the chamber and the chamber motor, but instead the temperature sensor located under the front bonnet. I'll try to post those pics and a quick writup to this post soon so it will be in the archives for others.
-Skip
Great pictures. I just fixed a similar problem recently and took some pics, but haven't posted them yet. My problem was not the chamber and the chamber motor, but instead the temperature sensor located under the front bonnet. I'll try to post those pics and a quick writup to this post soon so it will be in the archives for others.
-Skip
01-05-2005, 03:17 PM
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Climate control incorrect air temp hot or cold
Great! Obviously, this climate control system is super complex with many variables but when certain symptoms can be traced to a small number of causes others may benefit and save $$.
The repair I described is really easy, BTW, if you are purchasing the motor and just going to remove and replace. 15 minute procedure.
The repair I described is really easy, BTW, if you are purchasing the motor and just going to remove and replace. 15 minute procedure.
