Heater not working?

Hi,

Based on your description, it sounds like the engine coolant is low. Have you checked that? Take a look through this link and let me know if it helps:

https://www.2carpros.com/articles/car-heater-not-working

There is what is called a blend air door actuator that is responsible for the air temp entering the vehicle, but I don't think that is the issue here. It wouldn't change directions based on if the vehicle is in park or moving.

Let me know if the above link helps. If it doesn't we'll move on.

Take care,
Joe

Check for vacuum leaks to vent door actuators under dash, and with the engine hot, running, the heater on, feel both heater core hoses. Are both hot? If so, check blend air door. If only one is hot, flush heater core.

Check actuators in heater box if hoses are both hot. If hoses aren't hot then check water valve for operation. It is vacuum operated so check for a vacuum line off or see if it's getting vacuum, if it does the motor isn't any good as it's not opening. It is item 1 in pic.

It sounds like you have a blend door actuator that has gone bad for the temperature. Here is a guide that gives you an idea of what you are in for when doing the job.

https://www.2carpros.com/articles/replace-blend-door-motor

and

https://www.2carpros.com/articles/car-heater-not-working

Here are diagrams of what it like on your car. (below)

Please let us know if you need anything else to get the problem fixed.

Cheers, Ken

You system is vacuum operated doors. See if both heater hoses are hot when truck is warm. Then see if vacuum motor on hvac unit is getting vacuum so the door will open. If not check for a vacuum leak, you might hear a hissing sound under dash if it's leaking.

If you brought the car in for A/C work and the same day you picked it back up the heater did not work, they are responsible for it. Obviously they are not going to want to fix something for free. But if they messed with wiring under the dash checking things or whatever, its up to them to fix it. Issue is, you should have brought the car right back the same day and addressed it then. After waiting a month, they now can say anything.

Good afternoon,

Yes, I would flush the heater core.

https://www.2carpros.com/articles/car-heater-not-working

Remove both hoses and use a garden hose to flush the core. Run it back and forth through the core until you get a good clean even flow. Then hook the hoses back up and see if you have heat.

If not, then the core will have to be replaced.

Roy

REMOVAL
1. Remove the evaporator core housing.

NOTE: If a heater core leak is suspected, the heater core must be leak tested before it is removed from the vehicle.

2. Remove the instrument panel. Refer to: Body and Frame, Interior Trim, Dashboard/Instrument Panel, Service and Repair, See: Dashboard / Instrument Panel > Procedures > Removal and Installation

3. Remove the Powertrain Control Module (PCM).

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4. Remove the PCM heat sink.
1 Remove the ground strap screw.
2 Remove the heat sink.

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5. Remove the four nuts from the engine side of the dash panel. Position the plenum chamber on the vehicle floor.

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6. Remove the heater core cover.
1 Remove the screws.
2 Remove the heater core cover.

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7. Remove the heater core.

INSTALLATION
1. To install, reverse the removal procedure.
During installation, be sure to install a new oval foam seal around the heater core inlet and outlet tubes.

There is not heater control valve for this system.

The door or the blend door is what turns off the heat.

Roy

The second picture shows a control valve. Try moving the arm manually and see if the hose gets hot and you get heat.

The blend door look right and also new.

Roy