Just a guess, but at least some GM's take the vacuum from a plastic
probably located under the hood. I would look around there. Some of them
are rather easy to snap off the little plastic connector. I have drilled
and replaced them with brass or plastic hosenoses from the hardware store.
If it isnt at the cannister, you can probably trace the vacuum lines and
find one cracked or disconnected.
Most definitely a vacuum connector. The vents are switched by
vacuum-operated actuators; no vacuum, no switching. Do yourself a
favor and do NOT pull anything apart inside the passenger compartment,
dash, etc. It's in the engine compartment.
Look for hoses that are loose, brittle, or worn from rubbing against
other parts. They should fit on the connecting nipples snugly; if
not, replace the hose. With a car of your age, my procedure is
usually to change 'em all. You can grow gray tracing vacuum hose
leaks on an older car. Life's too short.
-= Larry A.
On Mon, 24 Oct 2005 23:51:40 -0400, "baldballdad"
Open the hood and the vacuum reservoir is the large black ball shaped
item attached to the hood to the right of the latch area. It has one
line that connects to it. That line will go down to a check valve
mounted on a short line toward the rear of the intake manifold (pull the
doghouse cover for better access to it) On that valve is a second
fitting that goes inside to the heater controls. Check all the lines and
the valve and ball for leaks. The valve can be tested by blowing through
it gently, if you blow into the side with 2 ports air should come out
the other side. If you blow through the side with 1 port it should not
allow air through.
"Larry A." < firstname.lastname@example.org> wrote in message
actually, 93's use a stepper motor to control the ducts. if your
have a digital display, is there anything flashing on
it? that flashing will
usually indicate a problem, but - like i
said, on 93's, you don't even have to
have the engine running to make
the ducts change from floor, to dash, to defrost
- you adjust the
controls, & you can hear the stepper motor moving the ducts. i
was surprised too, but it's true.
The 95 that I have has vacuum controls for the heat/AC. Plus a
> cable for Hot/Cold. 96 was the redesign year that included a lot of
hmmmm, i wonder why my 92 has electric step motors that
vents then - my a/c controls are electronic - there are no cables at
all - the hot - cold control is digital, & you move it up or down
on an LED type
display (that will also blink out error codes when
there's a problem). no
vacuum anything in it (unless you wanna count
the inlet side of the fan)
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