I have a 92 Pontiac Grand Prix and suddenly, the 'vent' switch doesn't
shift the air flow through the vents on the face of the dash. Blower
only blows through the floor or defrost. Is there some sort of relays
that may be acting up and not allowing this to switch properly? The
heat control switch on the dash indicator lights function properly but
the actual switching of air isn't taking place. This problem seemed
to coincide with when I changed the car battery but that may just be a
coincidence.

Summer heat is such that the AC just can't get enough cool air into
the car through the floor vent so I'm anxious to get this fixed.
thanks very much for any pointers...

John

On Sat, 16 Aug 2008 11:05:46 -0700 (PDT), jcage@lycos.com wrote:

>I have a 92 Pontiac Grand Prix and suddenly, the 'vent' switch doesn't
>shift the air flow through the vents on the face of the dash. Blower
>only blows through the floor or defrost. Is there some sort of relays
>that may be acting up and not allowing this to switch properly? The
>heat control switch on the dash indicator lights function properly but
>the actual switching of air isn't taking place. This problem seemed
>to coincide with when I changed the car battery but that may just be a
>coincidence.
>
>Summer heat is such that the AC just can't get enough cool air into
>the car through the floor vent so I'm anxious to get this fixed.
>thanks very much for any pointers...
>
>John


The back of the heater/AC control has wires and a vacuum switch and
maybe a cable. The vacuum switch has fallen apart. It's held in by
a "speed" nut affair and the cheap plastic has let it go. If you can
find all the pieces you may be able to reassemble or find another at
the wrecker.

P