Air Conditioner only works on defrost?

Hi,

Are you able to change the airflow direction when you are not using the AC? The airflow direction is controlled by the mode door actuator. That's why I'm asking.

To answer your question, the blend door actuator is only responsible for the air temperature entering the vehicle. It won't change the air flow direction.

Let me know.

Take care,

Joe

Thank you for your response. Correction, it is the mode door actuator that I’m replacing. Also, I took apart the mode switch on the dashboard and cleaned the contacts on the inside of the knob.

Normally as long as the fan was on and the A/C button was pushed, the green light would turn on and I could use different modes with the A/C working. Now it just works on defrost.

My main question here is, does the mode door actuator have to be connected in order to turn on the A/C? Right now, that motor is out and will only get A/C when defrost is selected. What I did was move the controls behind the dashboard by hand to make the A/C blow out the dashboard vents until I get the mode actuator installed.

To follow up the mode door actuator was installed and works properly, however, the air conditioning only works when on defrost. Is it possible it’s a mode switch on the dash that’s the problem?

Hi,

It sounds that way. If the actuator is working properly, the AC should work correctly.

Does this vehicle have automatic climate control or manual control? I started digging through wiring schematics, and they are very different.

Let me know.

Joe

It has manual climate control. I’m almost suspecting it’s the actual A/C button itself. When I pull the relay and use a test light, it’s the same two terminals that stay lit with the button pressed and de-pressed. My thoughts are if the A/C button was doing its job it would make one of the other terminals light up.

Hi,

A relay is set up with a primary (pins 85 and 86) and a secondary side (pins 30 and 87).

On the secondary side, either pin 30 and 87 will have power at all times. The opposite pin in the secondary will not have power until the relay is actuated. Then the power runs to the component.

On the primary side, either pin 85 or 86 will have power when the button (in this case) is pressed on. Once that power becomes present, the opposite pin on the primary has to provide a ground path to complete the circuit.

Once the primary is completed, it becomes an electromagnet and draws the switch closed on the secondary side allowing power to reach the component.

Here is a link that explains it in more detail:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Is this automatic or manual climate control?

Let me know.

Joe

Thanks! I will definitely test this! I did swap out the horn relay with the AC clutch relay and it was still doing the same thing.

This is a manual climate control system.

I ordered an A/C button from Walmart for $10.00. I’m going to replace that as well and see if that’s the problem.

One thing I want to mention is when I had the climate control panel out of the dashboard looking at the connections on the switches the 10A magnetic clutch fuse under the hood for the A/C blew out. I replaced it with a 30A fuse. The A/C ran for a little bit then stopped. The 30A fuse was fine when I checked it and the A/C will run fine, but only when in defrost.

Hi,

If you replaced it with a higher amperage, that isn't safe. If there is a short, the wiring could burn before the fuse fails. I would replace it with the correct amperage fuse.

It's odd the compressor clutch fuse would fail by removing the panel. Inspect the wiring at the panel to make sure nothing is exposed and able to short.

Let me know.

Joe

Hello,

The issue has been resolved and it was the A/C button.

The two facts that led me to it being the button inside the car were.

The “Clutch Mgmt” relay under the hood was taken out and upon pressing the button to turn on the A/C, the contact that should have made the test light illuminate didn’t light up.

Upon disconnecting the wiring clip with the 5 wires that goes to the back of the A/C button, the blu/red had live power as it should have. However, it was not completing the circuit inside the switch to transfer voltage to the red/blk wire which tells the compressor to turn on when the fan is on. To figure this out I took a paper clip, placed one end on the blu/red contact and the other end on the red/blk contact. Lone behold it turned the compressor on regardless of what mode the fan was on.

Thank you, Joe, for your help in this and hopefully someone with this same issue can efficiently resolve this with knowledge shared here.

Hi,

You are very welcome and I'm glad to know the problem has been resolved. Also, thanks for the update. I know it will help others.

Take care of yourself and feel free to come back anytime in the future.

Joe