First I would like to say hello! I am happy that I have found a cool site dedicated to T-birds and Cougars! (http://bestsmileys.com/happy/7.gif) Also, don't let the fact that my screen name is 871Chevelle fool you, I am a bigtime Ford fan as well!
Anyway , I am having a little issue with my Cougar and thought that this would be the perfect place for some suggestions! So here it goes...
I have a 1993 mercury Cougar XR7 with a 3.8L v-6, and a AOD trans. I bought this car brand new in 1993 and have had no issues with it untill now. Heres the problem ...
The heater and a/c work fine, but comes out on defrost and floor only, and will NOT come out of the dash vents..(http://bestsmileys.com/angry2/6.gif) I know it is vacume operated, so I removed the controls and glove box to check for vacume, and it pulls strong.
When I turn the controls to a/c or vent, I hear a constant 'hissing' sound like there is a vacume leak. When I select any of the heat options, the 'hissing' sounds goes away, reguardless of what I have the settings at, the blower motor will only push air through the defrost or floor vents, and not the dash vents.
I inspected every inch of the vacume hoses both under the hood and behind the dash and everything looks perfect.
Is it possible that the actual heater control assembly is bad? Or is there some sort of blend motor or something somewhere?
What would cause the air NOT to come out of the dash vents, but only the defrost and floor?
Thanks so much in advance
It comes out the same no mater where you set the selector, even if it's just set to one position
It does? So when I set the controls for the air to come out at the floor, it's supposed to come out the defrost vent? And when I turn the a/c on, it's supposed to come out the defrost vents instead of the vents on the dash? I never seen anything like that before. For the first 14.5 years I have owned the car, its always come out where I selected ... Defrost, floor, or vents. Your saying that its supposed to come out the defrost only? If thats the case, I want to break it like it was for the first 14.5 years! :confused:
I think he forgot the question mark - trying to get more info :D
The vacuum selector switch possibly? It should have a line running to it.....I believe it's behind the heater control assembly.
Sorry, I forgot the ?
It does sound like the vac. selector. It could be why it's hissing too.
BTW.... Welcome aboard
The A/C-Defrost door is staying in the No-Vacuum position.
With the selector in the defrost or floor position, no vacuum is sent to the A/C-Defrost vacuum motor.
With the selector in A/C you are hearing the vacuum thats supposed to go to the A/C-Defrost vacuum motor leaking.
The vacuum motor operates the door with a cable.
Thanks for the comments and suggestions guys! (http://bestsmileys.com/dancing/4.gif)
I was wondering what you mean Daminc, but the missing ? sums it all up! Thanks for getting back to me and the welcome! (http://bestsmileys.com/thumbs/2.gif)
I'm still dont understand what is going on though with the dash vents not blowing any air, and when it is supposed to get vacume to switch the blend motor. I unplugged the vacume harness and started adding vacume to each hose seperately. I could hear the blend door moving sometimes, but all I get is the defrost or floor only.
According to Softtouch, are you suggesting that there is a vacume leak somewhere? Or is that hissing sound normal when the controls are on A/C?
Heres what I'm looking at. Does anyone know what color hose would operate the dash vents ??? ....
(http://i189.photobucket.com/albums/z307/bb66chevelle/Cars%20II/HPIM2074.jpg)
(http://i189.photobucket.com/albums/z307/bb66chevelle/Cars%20II/HPIM2073.jpg)
Thanks again guys!
Yes I am saying you have a vacuum leak.
I only have documentation for 84 and 87 and the color codes don't match.
Your vacuum lines go to vacuum operated motors.
The motors operate the doors in the air box.
One of the doors directs the air to either the windshield or the dash vents. When you put the selector in a position to move this door to the dash vent, you hear a vacuum leak and the door doesn't move.
Thanks again for the reply Softtouch!
I got the car outside on my lift checking things over for a little road trip. But as soon as I bring it back down I will pop everything apart and search around for a broken or unhooked vacume hose going to any of the vacuum operated motors.
I know when I had it apart the first time I didnt see any motors or anything with all the clutter behind that dash! But according to you great folks it is mounted to the heater box somewhere, so I will find it!
From messing around with it, I know that the grey hose is the engine vacume, but I dont know what the other ones are either. Theres also a yellow one coming off the back of the controls that appears to drop down near the front of the center consol?
Anyway, thanks so much and I'll post back with my results!
Joe
I might suggest you try this question at http://www.tccoa.com they cover the mn12 cars a bit better than us.