Nissan Repair: heater, nissan maxima, vacuum motor

Question
heater will not work in a 1992 nissan maxima, when you move the lever to hot the gate moves normally, it was working but not consistant work/not work, now will not work at all, the fan works normal, it doesn't run hot or anything, has plenty of coolant, please help

Answer
James,

It is either a vacuum hose or a cable that is not moving the blend door.  Take the glovebox out and look behind it and you will see the heater box.  Follow the hoses from the control panel to the box and you will find the problem.  There will be a metal arm that looks like a piece of welding rod that extends form the box.  A vacuum motor or a cable will connect to this arm and that is what moves the door.  If you hear vacuum while you are running the engine and moving the control from cold to hot you should find the problem easy.