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Discussion Starter #1
Hello. I bought a 96 DeVille and this is the first winter driving it. It doesn't seem to get very warm inside. We're getting our first real snowfall and the temps have dropped. I do get warm air from the windshield defrost when I turn that on, but I never feel anything from the floor! Am I doing something wrong? I hear the blower fan running, have the temp at 90 degrees, but without the windshield defrost on, I'd freeeeeeezzzzzze! :mad: Any suggestions on what to look for or do would be greatly appreciated!

Thanking you in advance and have a Happy Thanksgiving!
 

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White Diamond '03 DHS (with DTS floor shift)
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Defrost is the default setting. If you cannot get heat anywhere else, you likely have a vacuum leak in the line somewhere. The parking brake release is vacuum operated and on the same vacuum circuit. Does it release properly?
 

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White Diamond '03 DHS (with DTS floor shift)
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Releasing is vacuum related. Engaging is not. That needs adjustment. Probably at the cable adjustment where it "Y"s (under the car below the drivers seat).
 

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Discussion Starter #5
Ranger said:
Defrost is the default setting. If you cannot get heat anywhere else, you likely have a vacuum leak in the line somewhere. The parking brake release is vacuum operated and on the same vacuum circuit. Does it release properly?
I just went out and tested it. I put the parking brake on (first time I've used it!) and then pulled the tranny into drive to release it. It did release, but it was slow and I did have to put my foot behind it to make it go all the way off. It is pretty cold here though. If it is a vacuum leak, is that something I can fix myself? Does it need to go to a dealer? I truly appreciate your time.

Thanks.
 

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White Diamond '03 DHS (with DTS floor shift)
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Sure you can fix it yourself, if you can find it. The fact that it is releasing indicates the you must have some vacuum. Get a hand held vacuum guage, pull the vacuum line off the parking brake diaphram and plug the guage onto the line at idle and see what kind of vacuum you have. Now do the same thing at the cabin source. That would be where the vacuum line comes into the cabin at the firewall on the passenger side. If it is higher at the source line, then your problem lays between. You'll have to trace the lines under the dash. If it is the same, then I would suspect the reservoir or check valve at the reservoir. The reservoir is under the battery shelf and is not uncommon to develope a crack or have the check valve go bad. A stethescope is a great aid in locating a vacumm leak.
 

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o yeah i know the engaging is cable related and under the car, but i didnt know the release was vacuum controlled..wen i put it in drive i have to take my foot behind it and pull it towards me, it has no vacuum at all
 

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A setting of "auto" and 90 degrees should blow warm air at your feet.
I would agree that if it doesn't you likely have a vacuum leak.

As said you could fix it yourself... if you can find it.
There are many possibilities though and it might not be very easy.
If there was no vacuum to the park brake release, putting your foot behind it would make no difference. It would stay down.
If memory serves, open the hood and remove the engine cover. There should be a small vacuum line on the passenger side of the engine that goes over toward the strut tower. There is a small check valve in it and then I think it splits. One line goes down to a vacuum "ball" under the right front of the car and the other goes inside to feed vacuum to the control solenoids that control the mode doors.
A leak in any of those lines will cause this type of problem. Also the solenoid pack (again that's if my memory is working today) could be faulty.
Control head failures are rare.
One of the mode diaphragms could be bad also but that is even less likely.
 
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