Low air flow out of vents?

Hi,

The airflow direction is controlled by a vacuum-operated mode door. There is a chance the vacuum is weak, there is a small leak, or the actuator is going bad.

If you look under the dash, there are two actuators to look for. One is the panel/defrost and the other is the panel/floor actuators. I attached pics below.

Here is what I need. First, pay attention to see if there is any airflow from a different location when the panel is selected. If there is, the first pic is the panel/floor actuator and the second is the panel/defrost. Focus on the one that seems relevant.

If there is no air coming from a different location, with the engine running, see if you can hear a hissing or anything that could indicate a vacuum leak.

Let me know.

Joe

See pics below.

What is the main vacuum source for these acuators?

Hi,

The primary vacuum supply is from the engine. There will be a vacuum line on the intake manifold that runs into the vehicle and is distributed by the controller.

I need you to pay attention to something for me. Find a steep hill and see if when climbing it if the airflow changes direction. We could have a leak somewhere else which is lowering the vacuum enough to cause this to happen. It would be a good idea to check if you can find any leaks.

Here is a link that explains how to locate and repair one:

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

Let me know if that helps. Also, let me know if the engine has a smooth idle or if it is rough.

Take care,

Joe

Thanks.
The engine is not running rough.
There is a vacuum actuator on the right side that appears to be working. There is an electric actuator on the top, which is turning, controlled by the temperature selector switch.

Not many hills in FL.
Sometimes I notice a slight increase in air flow when the outside temperature is lower.

Could there be debris coming off from the blower to the coils?
If so, can this be accessed by removing the blower?
Is there another vacuum actuator that I am not seeing on the left side?

Hi,

There are two. Did you locate the ones I indicated in the pics above? Also, if you have, I want you to try something. You should be able to see the actuator move when selected. With your fingers, see if you can pull it further than it goes on the engine vacuum. If you can, see how it affects the airflow.

Let me know.

Joe

Checked vacuum lines and appear good.
Checked accumulator and more vacuum in than out.
Only found 1 vacuum actuator and 1
electric actuator on top.. fresh air actuator is working.

Very little air coming through the defrost.
Could it be the blend door actuator?

Hi,

The blend air door is responsible for the air temperature coming into the vehicle. So, I would say no.

Do me a favor. Take a look at the schematic below and let me know if your vehicle appears to be set up the same way. Everything I'm seeing shows the mode doors are vacuum and there is more than one.

Let me know.

Take care,

Joe

See pic below.

Good vacuum. Checked the line from reservoir and there was still vacuum when I pulled off hose. No other vacuum actuator, only fresh air on right.
I do believe there is a solenoid actuator right next to the blend actuator.
The solenoid does get warm. You can see it in one of the pictures.

P/n 1F20-61-K1Z

Hi,

Which picture are you referring to? Is it one that you already attached?

If the vacuum is good, have you watched to see if the actuator is responding? Also, everything I have shown is more than one vacuum actuator. I looked at your second pic above and there are five vacuum hoses I see in the pic. Where do they all go?

Joe

This is a connector and hoses go into box.

Here is s pic of vacuum fitting.

Hi,

That appears to be the A/C mode switch. It shows the vacuum going to the panel/defrost actuator. I highlighted it in the pic below.

If that actuator is getting vacuum and not leaking, there could be an issue with the door itself.

Let me know.

Joe

See pic below.

Mystery solved.
Removed blower motor and found a clogged evaporator core. I took a shop vac and a garden hose to flush out debris.

Thanks for your help in trouble shooting this issue.
Full air flow now.

Hi,

Thanks for the update. It certainly looks clogged. Regardless, I'm glad it's cleaned out and working properly for you.

Take care and please feel free to come back anytime in the future. You are always welcome here.

Joe