Nissan Repair: location of firewall and cut off on a 2003 nissan exterra, nissan exterra, glovebox

Question
Need to find out why heater doesn't work.It only blows cold air.  

Answer
George,

Follow the hoses from the engine to the firewall and you should find the valve on one of the hoses.  The problem might be inside the vehicle due to a blend door malfunction.  That is, the door that moves and lets heat in might be stuck or the actuator might be defective or the connection has come off.  Get under the passenger side of the dash and watch the blend door motor when you move the system from airconditioner to heat and see if it moves properly.  You might need to remove the glovebox to get a good look...