Heater Blows Hot Air Only

[BuffPath]

Hi everyone! My heater blows hot air when it is switched to Off position and the dial just one click above 65 or higher. Put it back to 65(coldest) and it blows cool air. So the temp choices are either cool or super hot. It just started doing it. What do I need to check/replace? Let me know if you need more info. Thanks!!!!

Edited April 9, 2010 by BuffPath

[4X4pathy94]

lol.. Mine is doing something like that only mine is stuck completly on high heat.. i can choose through the low mid high settings but that is it. I havent done any tinkering with it yet but i will have to soon before the heat waves get here.

[adamzan]

Brandon yours is disconnected at the linkage.

[Kingman]

I'd imagine it's vacuum assisted, no? There should be mixture "doors" coming from the heater core that move when a signal is given to mix the hot and cold air flows to create an ambient temperature. Usually they are controlled by vacuum, which is first controlled by an electrical solenoid linked to the control knob. Change the temperature, the electronic signal is sent to a vacuum motor, which moves the doors around. That seems to be the most common set-up for climate control systems. Nissans may be different though.