Where is the blend door located?

Hi,

Does the air come out at any point in the vehicle? The idea that you hear it running, it should be at some point.

Now, I have a question. You mentioned the blend air door. That is what controls the air temperature coming from the system and not the airflow direction. Is the temperature the issue or the airflow direction? Also, has the blower motor recently been replaced?

If you look below, I attached a few pics to help you locate the actuators. Note that these actuators are not electric, but rather are operated by engine vacuum.

In pic 1, it identifies the component locations. If it is the temperature that is the issue, focus on the temperature valve. If the problem is airflow direction, focus on the A/C defroster valve.

If I had to guess, I have a feeling you lost the vacuum to the unit altogether. So, it is a good idea to check for vacuum leaks at the controller on the dash. Also, if there is a leak under the dash, you may hear a hissing sound where a vacuum hose has failed. So, with the engine running, see if you can hear anything like that. Additionally, note that in pic 1 the hoses are identified by color. So, it may be easier to locate the hose under the dash you are questioning and follow it.

If you find there is no vacuum supply from the engine, open the hood and take a look at the vacuum hoses to the intake manifold. There will be one that runs to the firewall and into the vehicle. Here is a link as well that explains how to locate vacuum leaks:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Take care and let me know what you find or if you have other questions.

Joe

See pics below. Note: Pic 2 is a description of the heater valve. I thought it may be of interest to you.