AC Vent Door Clunk
Thread Starter
Le Mans Master
Joined: May 1999
Posts: 6,517
Likes: 1,304
From: Windermere FL
AC Vent Door Clunk
On my 90 with C68, whenever you change the AC controller from off to any position, there is a small delay and then you hear a clunk. Like the vent is being held in position and then frees up suddenly. Same happens if you have it in any position (other than off) and startup the car.
Almost acts like something dropped down the vent.
I have no desire to trear down the dash to figure this one out. Any tricks out there to figure out what is causing it to stick?
Almost acts like something dropped down the vent.
I have no desire to trear down the dash to figure this one out. Any tricks out there to figure out what is causing it to stick?
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
There is a motor driven mix door that is sticking, or moving slowly.
I have a problem with that device sometimes not functioning and may have to tear into it. I too don't look forward to that "adventure".
But I look forward to any knowledgable replies on the topic.
I have a problem with that device sometimes not functioning and may have to tear into it. I too don't look forward to that "adventure".
But I look forward to any knowledgable replies on the topic.
Thread Starter
Le Mans Master
Joined: May 1999
Posts: 6,517
Likes: 1,304
From: Windermere FL
Originally Posted by 65Z01
There is a motor driven mix door that is sticking, or moving slowly.
I was thinking that it was vacuum operated and that when the car sits the system looses vacuum. Does not occur once the car is operating and I change it off/on or to different settings. And it also happens even if the engine is off for only a little while.
Was thinking about putting in some kind of one way vacuum valve so that it would maintain the vacuum in the system when the engine shuts off. But that would probably not really help as it would be too easy.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Could be any of the doors - most of my GM cars have made a clunk when the outside air door closes for recirculation. Electronic Air does cycle the Temp Door under certain conditions. It's calculating, electronically the position of the door and it does this by opening and closing it. There will be brief delay while this process takes place. Unless you have a real big "thunk", I wouldn't worry about the noise. Toyota and the Asian manufacturers probably do a better job keeping things quiet and the noise your hearing may just be typical of Ford, GM, etc.
Thread Starter
Le Mans Master
Joined: May 1999
Posts: 6,517
Likes: 1,304
From: Windermere FL
SunCR,
Your advice is probably best - I sure don't want to tear the dash down for a clunk. But this clunk is new and was never present during the car's first 14 years or so.
But the old saying, if it still functional, don't fix it seems to apply I guess.
May she developed authritis?
Your advice is probably best - I sure don't want to tear the dash down for a clunk. But this clunk is new and was never present during the car's first 14 years or so.
But the old saying, if it still functional, don't fix it seems to apply I guess.
May she developed authritis?
