2003 ford taurus blows cold air out the defrost

SOURCE: Vent control

You have a vacuum leak.Defrost is the default postion(no vacuum).
See if you can locate the small black vacuum line that goes inside the vehicle on the passenger side near the heater core. The trace it back,should see it going to a canister then to the intake manifold.Make sure it is not disconnected or broken somewhere.

SOURCE: heater is blowing but its cold air not hot air 2000 expedition

Make sure the heater core is in the open position by using the shut off valve and turning it to open. next, you may have a malfunction in the direction door the directs the air flow in the dash. a lever may have become lose or separated. may be a bad servo motor not directing the door to move to the heater position. i would start by checking that shut off valve first on the heater core.

Marvin

• 85242 Answers
• Posted on Aug 14, 2009

SOURCE: I have a 2006 Ford Expedition. The Air

you have a vacuum loss to the ac control head, the motors that divert air are vacuum operated, if you loose vacuum the system goes to defrost for safety reasons, the vacuum comes from the engine, then goes o a plastic vacuum tank under the hook start there, it is a 3/16 id hose.

SOURCE: heater blows cold air have replaced the thermostat

sounds like the controller went bad use temp checker see what your temp is at inlet of heater core from hose

SOURCE: 2001 ford taurus wagon/air only flows through defrost vents

you have a vacuum leak check vacuum lines