2004 Buick LeSabre Floor Vents Only

Hi,

It sounds like the mode door actuator has failed. The mode door is what changes air flow directions. I would remove it and check to see if it is operating when you change directions. If not, replace it. Here is a guide to help you step by step with instructions in the diagrams below to show you how on your car.

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

Here are the directions specific for your vehicle as far as replacement. The attached pictures correlate with the directions.


MODE ACTUATOR REPLACEMENT

REMOVAL PROCEDURE
1. Remove the left sound insulator.
2. Remove the knee bolster.
3. Remove the IPM.
4. Disconnect the electrical connector from the mode actuator.

5. Remove the mode actuator retaining screws (1).
6. Remove the mode actuator.

INSTALLATION PROCEDURE

1. Align the mode door levers with the cam slots.
2. Install the mode actuator.
3. Install the mode actuator retaining screws (1).

NOTE: Refer to Fastener Notice in Service Precautions.

Tighten
Tighten the screws to 1.4 N.m (12 lb in).

4. Connect the electrical connector to the mode actuator.
5. Install the IPM.
6. Install the knee bolster.
7. Install the left side sound insulator.
8. Recalibrate the actuator.

If you look at the last pic, it shows location.

Check out the diagrams (Below). Let us know what happens and please upload pictures or videos of the problem.

Thank you Joe. That is exactly what it was. Removed the actuator, started the car, turned on the air, manually moved the doors to make sure air changed between vent, defrost and floor and it did. Now just need to install the new actuator. Thank you so much. You saved me approximately $300.00.

Oh, not to mention my wife's and my peace of mind.

You are very welcome. I'm glad you figured it out.

Take care and feel free to come back anytime. Also, if you need help or run into trouble when reinstalling it, let me know.

Joe

I'm sure there is a mode actuator somewhere like the blend door but I don't see it. Has electronic climate control with passenger controls

Good evening,

Good chance the mode door actuator is the issue. I attached a picture and the procedure for you to view.

Roy

1. Remove the left sound insulator.
2. Remove the knee bolster.
3. Remove the IPM.
4. Disconnect the electrical connector from the mode actuator.
5. Remove the mode actuator retaining screws (1).
6. Remove the mode actuator.

After removing the glove box I've found the actuator is laying there. It's not blowing out the dash vents now. The air blew fine yesterday. A few years ago I bypassed the heater core to just have A/C in Florida. I think the actuator under the dash behind the glove box isn't the problem? Maybe under the dashboard the actuator isn't controlling the air out the dash vents?

Good afternoon,

Most likely the mode door actuator has failed. It is under the dash and easy to access.

I attached the procedure and a picture for you to view.

Roy

1. Remove the left sound insulator.
3. Remove the electrical connector from the mode actuator.
4. Remove the mode actuator retaining screws (1).
5. Remove the mode actuator.

INSTALLATION PROCEDURE


imageOpen In New TabZoom/Print

1. Align the mode valve levers with the cam slots.
2. Install the mode actuator.

NOTE: Refer to Fastener Notice in Service Precautions.

3. Install the mode actuator retaining screws (1).

Tighten
Tighten the fasteners to 1.4 N.m (12 lb in).

4. Connect the electrical connector to the mode actuator.
5. Install the knee bolster.
6. Install the left side sound insulator.

Just wondering if this was on the driver's side or the passenger side. The diagram is exploded I see. Thank you, Eddie

It is on the drivers or left side as stated in the procedure.

Roy

That's great as it says left but one I looked at was behind the glovebox on the left so I got confused. Thanks, Eddie

You are welcome.

Always glad to help.

Roy

The mode door actuator is not working. I know it has to come out but I cannot figure how to access it. I can only get my finger tips in there. It is number 2 in the diagram. The actuator seems blocked by the dash structure.

Good afternoon,

Are you accessing it from the bottom?

I attached the procedure and a picture for you.

Roy

REMOVAL PROCEDURE


imageOpen In New TabZoom/Print

1. Remove the left sound insulator.
3. Remove the electrical connector from the mode actuator.
4. Remove the mode actuator retaining screws (1).
5. Remove the mode actuator.

After step #1 there is not enough room to reach up to get to the screws. Like I said, the dash structure is blocking access.

Are you sure you are on the correct actuator?

Is this auto climate control?

Roy

Yes, it is the CJ2 dual zone climate control. It is #2 in my attached picture.

Okay, that's the issue.

For the auto climate control, the actuator is at the top of the housing where you cannot access it without removing the dash cluster. It has to be moved forward to get to the actuator.

Is this something you will be doing yourself?

Roy

It is on the side per my attached drawing. I got it out and bench tested it and it worked. so now back to square one.

What drawing?

Roy

My original post. I attached a diagram. It shows the actuator.

You need to check for voltage to the actuator. Did you do that?

Roy

Yes. This is what I did:

There are 5 wires to the mode actuator:
Term 5 is Brown, that's battery.
Term 6 is Yellow, that's your control. you are looking for varying voltage with DVM when you change modes(bi, vent, heater, etc.).
Term 7 is Yellow, that's your ground.
Term 9 is Yellow/blk tracer, that is your position data.
Term 10 is Grey, that is a 5 volts ref signal for the position sensor.
Basically test 7 for ground, 5 for BAT voltage, and 6 for varying voltage..

Okay, does the motor work out of the car and hooked to the car harness?

Roy

Yes.

Okay, then the issue is in the case. The door is not moving.

Can you move the door manually without the actuator hooked up?

Roy

I could not using just my finger tips. I slid the actuator on and used it as leverage and the doors moved.

Then replace the actuator. It may be failing under load.

Roy

Will do. I want to thank you for sticking with me. This has been frustrating. I will update when I get the part.

You are welcome.

Always glad to help.

Roy

I need to know how to locate and fix my mode door actuator.

Welcome to 2CarPros.

Here are the directions for replacement. It is located under the dash on the HVAC box. See the pictures for location.

MODE ACTUATOR REPLACEMENT
REMOVAL PROCEDURE


1. Remove the air temperature actuator.
2. Disconnect the electrical connector from the mode actuator.
3. Remove the mode actuator retaining screws (1).
4. Remove the mode actuator.

INSTALLATION PROCEDURE


1. Align the mode valve levers with the cam slots.
2. Install the mode actuator.

NOTE: Refer to Fastener Notice in Service Precautions.

3. Install the mode actuator retaining screws (1).

Tighten
Tighten the fasteners to 1.4 N.m (12 lb in).

4. Connect the electrical connector to the mode actuator.
5. Install the air temperature actuator.
6. Recalibrate the actuator. Refer to Re-Calibrating Actuators.


Here are the re-calibration directions.

RE-Calibrating Actuators - HVAC System - Manual
Vehicle Heating and Air Conditioning Testing and Inspection Programming and Relearning RE-Calibrating Actuators - HVAC System - Manual
RE-CALIBRATING ACTUATORS - HVAC SYSTEM - MANUAL
CALIBRATION PROCEDURE
Use the following steps to perform the calibration update.
1. Turn OFF the ignition.
2. Remove the battery positive voltage circuit fuse of the HVAC Control Module.

IMPORTANT: The module memory will not clear if the battery positive voltage circuit fuse is installed in less than 60 seconds.

3. Wait 60 seconds.
4. Install the fuse.

Check out the diagrams (Below). Please let us know what happens.

the A/C no longer blows out of the dash vents, but will blow out of the defrost and floor vents. It just recently began this, but prior to this, it would blow out of the defrost and floor vents, then you could hear a "flap" close and the air would then blow out of the vents. Do you have any DIY suggestions?

The mode selection is done through a series of air doors that are operated by vacuum. When there is either a partial or total loss of vacuum, the system will default to either defrost or on some vehicles, heat. Acceleration can also have an effect on the doors for the same reason.

This guide will help

https://www.2carpros.com/articles/air-vents-stay-in-the-defrost-position

Look under the hood for a small black plastic hose coming through the firewall. Follow it to the vacuum source looking for any breaks, cracks or leaks. Also follow any other lines that branch off because they may go to a vacuum reservoir (storage tank) and a leak there will cause the same problem. Using a vacuum gauge to determine if you have full vacuum at any given point is the best way to find it. You can cut into the line anywhere and splice it back together with a piece of vacuum hose. Find the broken line, you found your problem.

Check out the diagrams (Below). Please let us know what happens.

Air won't vent from dash(only floor or defrost now). Replaced the controll unit in dash and guessing its a vacuum issue as can manually force the door to vent from dash. Question is where does the vacuum line originate. Want to check that end to see if still connected or worn. Any other ideas to check? Thanks CJ

My future wife has a 1995 Buick LeSabre that had the same problem. There are two parts to our solution. The majority of vacume lines were all rotted so I replaced them. In addition there is a three way check valve that had a hole melted in it. this check valve is connected directly to a vacume line leading into the fire wall from the engine compartment to the inside of the vehicle. Once all the vacume leaks were fixed everything else worked great. Also there is a vacume can on the drivers side all the way to the front near the head lamp of the vehicle. Be sure to check those hoses as well. The entire job cost less than $10 and I was able to find all the necessary parts at Napa. :D Good luck!!

The heater/air conditioning is stuck on defrost and floor and will not change to any of the other vents.

Hi,

The air flow direction is controlled by what is called a mode door actuator. On this vehicle, all actuators are controlled via engine vacuum which is supplied from the engine intake manifold via a black vacuum hose. That hose connects to the rear of the controller in the vehicle where you select air flow directions. Then, based on your selection, engine vacuum is routed to the different mode actuators which open and close different doors allowing the air to flow in different directions.

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Since you are getting air at both the defroster and the floor, I suspect the vacuum supply from the engine has failed. In most cases, the plastic hoses crack and break off. So what I need you to do is simply craw under the dash and locate the vacuum hoses to the rear of the controller. Locate the black supply hose and remove it from the controller. Start the engine and place your finger over the end of that black hose to see if there is a vacuum (suction) available from the engine. If there isn't, we will need to locate where the break has happened.

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I attached a pic below that shows the different actuators and vacuum lines. Note that I highlighted the supply. That is the black one you need to check.

Let me know what you find or if you have other questions.

Take care,
Joe

Would it have anything to do with the plastic cover over the blower motor?

I'm not sure what you are referring to. Are there vacuum hoses going to something at that point? If it is just a cover, I don't see how that would cause this.

Joe