'03 Suburban A/C Problem

Hi All,

I have a well maintained '03 Chevy Suburban Z71 which is no longer
producing cold, air conditioned air. I haven't played with AC for many
years so any guidance will be greatly appreciated.

First, the compressor is running, the hose running from the compressor
to under the firewall is cool to the touch. The return hose is
obviously warm.

There is a smaller tube coming from the firewall running over the
condensor which is ice cold, but there is a joint (compression fitting)
a foot later where the coolness basically stops...this tube continues
on to the top part of a 'Y', one section running back to the firewall
(warm), the bottom part running to something behind the headlight
(warm).

I'm at a loss here, and can't think of anything else to describe. I
can take pictures if it will help any. The problem I face is that
there are no local shops that can get us in until after the weekend,
but my pregnant wife isn't going to survive the 8 hour vacation trip on
Saturday in the heat and humidity. I think you see my problem.

Thanks for any help and suggestions.
Alex

Since you found the AC lines under the hood are cold it could be a
problem with the heater / AC controls inside the truck. The climate
control module might be telling the AC compressor to run, but it is not
opening or closing the right air doors to route air for the interior
vents through the evaporator. If you can reach the evaporator and feel
that it is cold then that would indicate the AC is ok but something is
wrong in the climate control system. If your truck has rear AC then
there might be a second evaporator that is more accessible then the one
under the dash. You might also check that the vents blow heated air
when the climate control is set to heat and Hot. If the vents just
keep blowing ambient temp air with the heater on then that would be
another sign the climate control system has a problem. Hopefully the
problem is intermittent and the system will start working again at
least for the weekend!

The www.rockauto.com catalog has pictures of many of the AC system
parts on your truck that might help you identify the different
components you are looking at.

wrote:
> Hi All,
>
> I have a well maintained '03 Chevy Suburban Z71 which is no longer
> producing cold, air conditioned air. I haven't played with AC for many
> years so any guidance will be greatly appreciated.
>
> First, the compressor is running, the hose running from the compressor
> to under the firewall is cool to the touch. The return hose is
> obviously warm.
>
> There is a smaller tube coming from the firewall running over the
> condensor which is ice cold, but there is a joint (compression fitting)
> a foot later where the coolness basically stops...this tube continues
> on to the top part of a 'Y', one section running back to the firewall
> (warm), the bottom part running to something behind the headlight
> (warm).
>
> I'm at a loss here, and can't think of anything else to describe. I
> can take pictures if it will help any. The problem I face is that
> there are no local shops that can get us in until after the weekend,
> but my pregnant wife isn't going to survive the 8 hour vacation trip on
> Saturday in the heat and humidity. I think you see my problem.
>
> Thanks for any help and suggestions.
> Alex

Hi Tom,

Thanks for taking the time to describe the troubleshooting steps, as
well as the things to start looking at. First, I realized from
rockauto.com that things aren't always as they seem...I called the
accumulator a condensor. Anyway, the good new is that I found the rear
air is working, which should get us through the long weekend. Good
call! Further testing shows that switching the front controls to heat
does produce hot air, while switching it back to cool produces ambient
air again. I'm not sure what this means, or how best to determine the
cause of the problem, but it probably means it is time to take it in
for a checkup.

Any last thoughts on the problem would be appreciated. Thanks again for
your advice and willingness to help!

-Alex




wrote:
> Since you found the AC lines under the hood are cold it could be a
> problem with the heater / AC controls inside the truck. The climate
> control module might be telling the AC compressor to run, but it is not
> opening or closing the right air doors to route air for the interior
> vents through the evaporator. If you can reach the evaporator and feel
> that it is cold then that would indicate the AC is ok but something is
> wrong in the climate control system. If your truck has rear AC then
> there might be a second evaporator that is more accessible then the one
> under the dash. You might also check that the vents blow heated air
> when the climate control is set to heat and Hot. If the vents just
> keep blowing ambient temp air with the heater on then that would be
> another sign the climate control system has a problem. Hopefully the
> problem is intermittent and the system will start working again at
> least for the weekend!
>
> The www.rockauto.com catalog has pictures of many of the AC system
> parts on your truck that might help you identify the different
> components you are looking at.
>
> wrote:
> > Hi All,
> >
> > I have a well maintained '03 Chevy Suburban Z71 which is no longer
> > producing cold, air conditioned air. I haven't played with AC for many
> > years so any guidance will be greatly appreciated.
> >
> > First, the compressor is running, the hose running from the compressor
> > to under the firewall is cool to the touch. The return hose is
> > obviously warm.
> >
> > There is a smaller tube coming from the firewall running over the
> > condensor which is ice cold, but there is a joint (compression fitting)
> > a foot later where the coolness basically stops...this tube continues
> > on to the top part of a 'Y', one section running back to the firewall
> > (warm), the bottom part running to something behind the headlight
> > (warm).
> >
> > I'm at a loss here, and can't think of anything else to describe. I
> > can take pictures if it will help any. The problem I face is that
> > there are no local shops that can get us in until after the weekend,
> > but my pregnant wife isn't going to survive the 8 hour vacation trip on
> > Saturday in the heat and humidity. I think you see my problem.
> >
> > Thanks for any help and suggestions.
> > Alex