'88 S4 HVAC Mixer Motor Location
11-02-2009, 01:41 PM
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'88 S4 HVAC Mixer Motor Location
The Hot/Cold slide control moves just fine but the temperature response is painfully slow (and becoming slower). Some listers say that the culprit may be the 'Mixer Motor', a small cigarette pack sized box with an extended moving arm in the center console behind the carpeted panel next to the driver's right knee. I've removed the panel but cannot find the 'MM'. Am I looking in the correct place? Any additional comments are welcomed. Thanks. Bob
11-02-2009, 01:46 PM
#2
Race Car
It's more like just forward and above your right knee. This page will help you:
http://www.millionaires-media.com/acprobs/
Dan
'91 928GT S/C
475hp/460lb.ft
http://www.millionaires-media.com/acprobs/
Dan
'91 928GT S/C
475hp/460lb.ft
11-02-2009, 06:31 PM
#3
Team Owner
the setting motor is usually the last thing to fail.
in order of failure
1. heater control valve and short hose, ( under the air cleaner)
2. vacuum pods under the center of the console
2a. Blower box vacuum pod
3. Blower motor relay pack
4. HVAC temp sensor string
5. HVAC head unit
google 928 keepers and follow the links look for Wallys HVAC systems
in order of failure
1. heater control valve and short hose, ( under the air cleaner)
2. vacuum pods under the center of the console
2a. Blower box vacuum pod
3. Blower motor relay pack
4. HVAC temp sensor string
5. HVAC head unit
google 928 keepers and follow the links look for Wallys HVAC systems
11-02-2009, 07:36 PM
#4
Drifting
I agree that if you have HVAC issues you need to work through things methodically rather than dive in. Great write up on John Pirtle's site, Wally Plumley's HVAC write-up and Dwayne's thread here on troubleshooting HVAC.
It's easy to do a quick check on mixer motor though. Once you've located it (it's on other side for my RHD so I can't be specific, but I think you have to remove parcel shelf to sight it regardless), shine torch on arm and move temp lever from full cold to full hot and you should see motor arm move between the two extreme positions.
Lots more promising candidates though for source of your problem as MrMerlin lists.
It's easy to do a quick check on mixer motor though. Once you've located it (it's on other side for my RHD so I can't be specific, but I think you have to remove parcel shelf to sight it regardless), shine torch on arm and move temp lever from full cold to full hot and you should see motor arm move between the two extreme positions.
Lots more promising candidates though for source of your problem as MrMerlin lists.
11-02-2009, 11:12 PM
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'88 S4 HVAC Mixer Motor Location
Dan, Graham's photo and labels at: 'millionaires-media.com/acprobs/' leave no mystery as to the location of the mixer motor. Thanks.
Mr. Merlin, Assuming that I find the mixer motor to be faultless, is there a place to go for the location and testing of each of your possible 5 systems causes?
1. heater control valve and short hose, ( under the air cleaner)
2. vacuum pods under the center of the console
2a. Blower box vacuum pod
3. Blower motor relay pack
4. HVAC temp sensor string
5. HVAC head unit
Stratford Shark, yes, the mixer motor first and simplest. Fingers crossed.
Thanks, guys
Bob
'88 S4 Auto Blk/gray
'00 DB7 Vantage 6sp Porsche Ocean Blue
Mr. Merlin, Assuming that I find the mixer motor to be faultless, is there a place to go for the location and testing of each of your possible 5 systems causes?
1. heater control valve and short hose, ( under the air cleaner)
2. vacuum pods under the center of the console
2a. Blower box vacuum pod
3. Blower motor relay pack
4. HVAC temp sensor string
5. HVAC head unit
Stratford Shark, yes, the mixer motor first and simplest. Fingers crossed.
Thanks, guys
Bob
'88 S4 Auto Blk/gray
'00 DB7 Vantage 6sp Porsche Ocean Blue
11-03-2009, 12:44 AM
#6
Team Owner
google 928 keepers and follow the links look for Wallys HVAC systems
Al;so go to 928GT.com and find page 2 then click on tips and links look for Wally HVAC
to do this first some trouble shooting is necessary but if the HCV is older than 5 years just replace it as well as the short hose.
The links will take you to HVAC pod diagnosis, and to temp sensor testing
Al;so go to 928GT.com and find page 2 then click on tips and links look for Wally HVAC
to do this first some trouble shooting is necessary but if the HCV is older than 5 years just replace it as well as the short hose.
The links will take you to HVAC pod diagnosis, and to temp sensor testing
