Nissan Repair: Heat, 2005 nissan pathfinder, nissan pathfinder

Question
QUESTION: My unit is blowing out cold air instead of heat.  What could be my problem?

ANSWER: Alice,

The usual cause is a defective thermostat.  If the thermostat is fine then you may have a plugged heater core.  Or, if you have had work done recently that involved flushing the coolant there might be an air bubble blocking coolant flow.  Email me back with the model and year and we'll go from there.

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QUESTION: Its a 2005 Nissan Pathfinder.  The heat works sometimes, but not most of the time.

Answer
Alice,

If you have it working sometimes and the temperature gauge reads normal then I would be looking under the dash for the blend door not working.  It would be the control on the dash or the actuator that moved the blend door from cold to hot.  Remove the glovebox and, with the engine running, look at the blend door actuator while you move the control from cold to hot.  See if ti moves or if something is preventing it from moving.