Start with: Possible control, blend door or blend door actuator, low pressure switch, leak in system.
Most temp blend doors have an electric actuator. The defroster, dash vents and floor vents are usually run by vacuum.
get a person who does that work to come over
First check the fuses then check your blower fan then check the blend door and blend door actuator and then the control panel
Not a whole of symptoms to work with here...The most common cause of "... heater not working..." is a failed temperature blend door actuator motor.See "Related Questions" below for more
Bad door lock actuator.
Deep under dash near heater core. Lots of work to get at.
Does your blower motor work? If it does and there is no heat the blend door actuator is probably not working and is not letting warm air into the vehicle. The blend door is staying in the cold position.
Cannot seem to get the air to flow throught the vents top or bottom. I have replaced the faulty blend door actuator loctaed on the side of the unit, but still no air or anything. Question: some one said that the openings have to be reset in order for the actuator to work, is this true? I do remember hearing a mechanic say that the way the original actuator came out is how the new actuator is supposed to go in. Please advice. Troy
If the antenna cable is loose, maybe.
Unfortunally you need to remove the entire dash assembly in order to gain access the the blend actuator. Consider replacing the heater core while your in there only because the amount of work involved to do it later if it should leak.
The BDA is mounted to the top of the plenum between the plenum and the duct work just behind the glove box