96 C4 AC/Heat Blower/Vent problem

My AC/Heat works great but it will not switch from blowing from the
floor vents to blowing out the dash vents, it use to do it aftewr a
few minutes or so but now it has stopped doing it and stay on the
floor vents no matter what switch location i put it on,should I assume
since I am having problems with my Cruise that I have a vacum problem
thats related to the venting system? I have the climate control
option. Any help appreciated.

Dave

wrote:
> My AC/Heat works great but it will not switch from blowing from the
> floor vents to blowing out the dash vents, it use to do it aftewr a
> few minutes or so but now it has stopped doing it and stay on the
> floor vents no matter what switch location i put it on,should I assume
> since I am having problems with my Cruise that I have a vacum problem
> thats related to the venting system? I have the climate control
> option. Any help appreciated.
>
> Dave
>
I had both symptoms in my '93. The vacuum check valves had gotten
brittle and cracked. It took several times to the dealer to get them
all, but now both dash controls, and cruise control are working well again.

Jim

"JimH" > wrote in message
...
> wrote:
>> My AC/Heat works great but it will not switch from blowing from the
>> floor vents to blowing out the dash vents, it use to do it aftewr a
>> few minutes or so but now it has stopped doing it and stay on the
>> floor vents no matter what switch location i put it on,should I
>> assume
>> since I am having problems with my Cruise that I have a vacum
>> problem
>> thats related to the venting system? I have the climate control
>> option. Any help appreciated.
>>
>> Dave
>>
> I had both symptoms in my '93. The vacuum check valves had gotten
> brittle and cracked. It took several times to the dealer to get them
> all, but now both dash controls, and cruise control are working well
> again.
>
> Jim

Boy, that sucks ;-))

"JimH" > wrote in message
...
> wrote:
>> My AC/Heat works great but it will not switch from blowing from the
>> floor vents to blowing out the dash vents, it use to do it aftewr a
>> few minutes or so but now it has stopped doing it and stay on the
>> floor vents no matter what switch location i put it on,should I assume
>> since I am having problems with my Cruise that I have a vacum problem
>> thats related to the venting system? I have the climate control
>> option. Any help appreciated.
>>
>> Dave
>>
> I had both symptoms in my '93. The vacuum check valves had gotten brittle
> and cracked. It took several times to the dealer to get them all, but now
> both dash controls, and cruise control are working well again.
>
> Jim

Ditto on my 96
Rob

--
Support www.HonorFlight.org
Show a Vet that you remember.

On Jul 12, 12:36 pm, JimH > wrote:
> wrote:
> > My AC/Heat works great but it will not switch from blowing from the
> > floor vents to blowing out the dash vents, it use to do it aftewr a
> > few minutes or so but now it has stopped doing it and stay on the
> > floor vents no matter what switch location i put it on,should I assume
> > since I am having problems with my Cruise that I have a vacum problem
> > thats related to the venting system? I have the climate control
> > option. Any help appreciated.
>
> > Dave
>
> I had both symptoms in my '93. The vacuum check valves had gotten
> brittle and cracked. It took several times to the dealer to get them
> all, but now both dash controls, and cruise control are working well again.
>
> Jim

Same w/ my '93. The culprit was located on the passenger-side under
the "Corvette" engine shield over the manifold. Just follow the vacuum
lines to identify it. Problem with mine was a crack in the neck of a
barb that entered the check proper. I was able to use some silicone to
repair the connection and now everything works fine. Good luck to
anyone with the same problem.

> '96vette
>
> > wrote in message
>
> oups.com...
>
> > My AC/Heat works great but it will not switch from blowing from the
> > floor vents to blowing out the dash vents, it use to do it aftewr a

Dave,

My '96 started doing exactly the same thing. The dealer thought it
was a computer problem and yours may very well be a vacuum problem but
the fix for mine was simply to refill the Freon and fix a slow leak.
It seems that the AC computer doesn't want to blow warm air in your
face so it waits until the evaporator coil gets cold enough before
turning on the dash vents which normally takes less than a minute. As
you lose Freon this takes longer and longer until the AC can't get the
coil cool enough to convince the computer to enable the dash vents.
It's still cooling and the floor vents feel cool but apparently not
enough. The C5's don't do this so I assume Chevrolet realized it was
a problem.