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1987 Coupe Deville
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17 Posts
Discussion Starter · #1 ·
My system seems to leak out a full charge after a month or so. This is the current condition, and the subject for another post. What has persisted is the inability of the system to send cold or cool air through the upper vents. I've had to rig an eye bolt, wire and dowel to the up-down door to get the air where I want it. I thought the problem might be the vacuum motor, so I pulled the vacuum connection from the programmer and tested that line with a vacuum gauge. It worked just fine. The system is getting good vacuum also, about 18 inches. Does this mean the problem is with the programmer? Other posts seem to say that they seldom fail, but, after all, this is a 34 year old car.
 

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Master of the Dark Art of Diagnostics
2003 DHS - two-2002 DHS, 2003 SLS, 1995 Sedan DeVille, 1989 Coupe DeVille
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21,439 Posts
My system seems to leak out a full charge after a month or so. This is the current condition, and the subject for another post. What has persisted is the inability of the system to send cold or cool air through the upper vents. I've had to rig an eye bolt, wire and dowel to the up-down door to get the air where I want it. I thought the problem might be the vacuum motor, so I pulled the vacuum connection from the programmer and tested that line with a vacuum gauge. It worked just fine. The system is getting good vacuum also, about 18 inches. Does this mean the problem is with the programmer? Other posts seem to say that they seldom fail, but, after all, this is a 34 year old car.
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first question is
does the automatic parking brake release work correctly?
it shares the same vacuum circuit as the climate control system -

IF you are getting full vacuum to the programmer -

and IF the various vacuum controlled MODE motors respond properly using a manual vacuum pump -
I would suspect the programmer -
 

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Registered
1987 Coupe Deville
Joined
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17 Posts
Discussion Starter · #3 ·
The parking brake releases, but often I have to repeat it just to get the brake light to turn off. That seems more an electrical contact defect; in the past I've tried to improve that, to no avail. As far as the other vac motors, they work. The one I thought wasn't opening properly is the outside air door, which the FSM shows having a "porous plug" in the vacuum line to slow or limit the air flow.
 
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