Where is the heater control valve? hot air blows from defrost or vents even when selector is set to cold.. please help..:stupid:?

Passenger side, below dash against the heater core housing,just follow the inlet hose to it. Sounds like your cable is bent broken or missing,it should be fairly easy to turn off by hand if the problem is not the valve itself.

Hope this helps

thank you... i will look at tommorrow..if it is a valve problem can i somehow turn off water to inside car til i find one? possible outside valve?

Yes,should be quite simple. Forgot to ask,what year? I'm talking about early years.

78 280z with air

I don't know then. The newer models may be vacuum actuated.

A 78 with factory air would have vacuum operated controls while a 78 with dealer installed air would have mechanical controls. If the first postion on your AIR lever is 'A/C' on your control panel and you have a 4 speed fan, it's factory air. If the first position is 'OFF' and you have a three speed fan, it's dealer installed or aftermarket air (or no AC).