OlschoolGs

i know most of the problems with the heating/ac comes from the valve that gets stuck(the one on the firewall) but a friend of mine is having a weird problem. no matter if he sets the climate control to inside circulation, air from outside gets in, when he puts on the heater, cold air from outside comes in, he puts on the a/c, air from outside gets in. is this from the climate control, or the valve/

turbogs300

most likely it's a valve, however, not the one on the firewall, it's the vacuum valve by the fan motor., probably the foam weatherstriping is long rotted and gone or the vave is shot.