I have a 2002 Sonata with 75,00 miles on it. Yesterday I used the a/c
with no problem. I then used the heater later that night. Now I can
only get it to blow hot air. No matter what setting I use, hot air
comes out of the vents. The compressor seems to be running and the
lines coming from it are very cold. I think maybe the heater switch is
stuck or something. Can anyone help? Thanks.

Duane

 

<duane.moseley@gmail.com> wrote in message
news:1164570494.358456.110980@l39g2000cwd.googlegr oups.com...
>I have a 2002 Sonata with 75,00 miles on it. Yesterday I used the a/c
> with no problem. I then used the heater later that night. Now I can
> only get it to blow hot air. No matter what setting I use, hot air
> comes out of the vents. The compressor seems to be running and the
> lines coming from it are very cold. I think maybe the heater switch is
> stuck or something. Can anyone help? Thanks.
>
> Duane

Sounds like the dampers that control air flow are not working. There is a
"blend door" that may be sticking or the controls not working. .

 

If you have cable-operated heater controls, you should check to make sure
none of the cables have come detached from the heater box.

 

hyundaitech wrote:
> If you have cable-operated heater controls, you should check to make sure
> none of the cables have come detached from the heater b

How do you know if you have the cable -operated heater controls?

Duane

 

You'll just need to stuff your head under the dash and look up at the
heater box. If there are cables attaching to it from the heater control,
you have cable-operated heater controls. Make sure the cam (the piece to
which the cable attaches) is in place, the cable ring is attached, and the
cable is clipped properly onto the heater box.

 

Sorry. Responded to myself instead of you, Duane. See my response to
myself above.

 

hyundaitech wrote:
> Sorry. Responded to myself instead of you, Duane. See my response to
> myself above.

I looked underneath the dash and near the center there is a plate with
a slot in it with a pin hanging down in one end of the slot. . When the
car is on heat the pin is in one side of the slot. When I switch it to
ac the plate moves about a half inch and the pin moves toward the other
end of the slot. I am assuming that it should move all the way to the
end of the slot to let ac air through. I tried to force it around but I
can't get it to budge. I don't see any cables but it looks like some
white gears on the other side of the plate that are controlling its
movement. Not sure if I explained that well enough or not. Thanks for
your help.

Duane

 

You're on the right track and you've found the right area if it moves when
you change the temperature. If you don't see a cable, there may be an
electric or a vacuum actuator there.