A/C problem, warm on driver side & cool on passenger side

[avisynth]

My car is lesabre 2000 limited with dual climate control.

The problem I met is that only passenger side blows out cool air. The driver side blows out warm air, just like vent.

I read some articles about the problem. The potential reasons will be:
1. No vacuum.
2. a/c programmer leak vacuum.
3. r134a is insufficient.
4. bad actuator.

What I did is:
Remove the glovebox and board above footwell on passenger side to check. But I can't find where are a/c programmer and actuator. There isn't any vacuum line. All is electrical lines. I find the blower ahead of the footwell, and it seems work well.

Could you please give me some suggestions?

Thanks in advance.

[BNaylor]

Welcome to AF.


Cool air or cold air? Being up North it should be cold. Best to check the refrigerant charge at the low side port and make sure it is in specs based on the ambient temperature. Even with the dual climate control system with two temp actuators always check the charge first. If low check for leaks.

[avisynth]

Thank you.
It is cold air from A/C since it is summer now.
I will check the r134a pressure at the low sided port and update it.

Originally Posted by BNaylor

Welcome to AF.


Cool air or cold air? Being up North it should be cold. Best to check the refrigerant charge at the low side port and make sure it is in specs based on the ambient temperature. Even with the dual climate control system with two temp actuators always check the charge first. If low check for leaks.

[polarzak]

Originally Posted by avisynth

4. bad actuator.

We had exactly the same problem with our 2000. The actuator was jammed. IT is up in the passenger foot well. You should be able to see it and the vacuum hoses after removing the plastic plates.
Good Luck.

[imidazol97]

Originally Posted by avisynth

My car is lesabre 2000 limited with dual climate control.
All is electrical lines. I find the blower ahead of the footwell, and it seems work well.
Thanks in advance.

The control for the passenger blend temp is above the blower motor on the right side of the HVAC box. It's up toward the heater controls.

In a corresponding position on the left side of the HVAC box is the control for the driver blend doors.

Good luck.

Many people have had low freon charge with the same symptoms. Are you able to change the temperature of air coming out of the passenger side vents? If so the passenger side blend is working. Are you able to change the temp on the driver side at all? Does it get warmer if you turn it hotter all the way hot? That means you are getting some movement on the driver's side in the driver's blend door and actuator movement.

[avisynth]

Thank you very much for the information you mentioned.

You are right.
I am able to change the temperature of air coming out of the passenger side vents by the temperature controller on passenger's door.

Also, I am able to change the temperature on the driver from cool to warm air. I can feel the air getting warmer when I change the temperature from 18 C to 32 C. As I mentioned, the only problem is that air from the driver side is not as cold as that from passenger side, when setting temperature 18C.

I will try to unmount the boards to find the actuator again.

thanks everyone.

Originally Posted by imidazol97

The control for the passenger blend temp is above the blower motor on the right side of the HVAC box. It's up toward the heater controls.

In a corresponding position on the left side of the HVAC box is the control for the driver blend doors.

Good luck.

Many people have had low freon charge with the same symptoms. Are you able to change the temperature of air coming out of the passenger side vents? If so the passenger side blend is working. Are you able to change the temp on the driver side at all? Does it get warmer if you turn it hotter all the way hot? That means you are getting some movement on the driver's side in the driver's blend door and actuator movement.

[imidazol97]

Originally Posted by avisynth

Thank you very much for the information you mentioned.

You are right.
I am able to change the temperature of air coming out of the passenger side vents by the temperature controller on passenger's door.

Also, I am able to change the temperature on the driver from cool to warm air. I can feel the air getting warmer when I change the temperature from 18 C to 32 C. As I mentioned, the only problem is that air from the driver side is not as cold as that from passenger side, when setting temperature 18C.

I will try to unmount the boards to find the actuator again.

thanks everyone.

Since both actuators seem to be working and are able to adjust the blend doors...

Have you had the freon level checked by someone with gauges for both high and low sides and who knows how to compensate readings for ambient temperature and for humidity?

The people who have observed this effect usually find the freon charge is low. The freon enters the evaporator on that system on the side where the passenger air goes through. So the expanding freon cools that side of the evaporator but has expanded and absorbed as much heat as soon as it enters the evaporator. Therefore when it gets to the side where the driver's air goes over the metal, the freon has little cooling ability, so the driver gets warmer air or air with more humidity left in it which makes it feel much warmer.

Try on a cooler day, driving at 40 mph and just keep the blower on a low speed setting for the air flow. If lower outside temps and low humidity help the driver's side air feel almost as cool as the passenger side, that would be an anecdotal proof that the freon charge is a factor.

Also, does your car have a cabin air filter? Has it been changed is or it stuffed up with dust and dirt and pollen.

[avisynth]

Thank you so much for the clarification. You suggestion is very helpful. I will have the freon pressure checked soon.

Yes. If the outside temperature is lower, the air from driver side feels as cool as the other side approximately.

My car has a cabin air filter, and I will check it later.

Thanks again imidazol97.

Originally Posted by imidazol97

Since both actuators seem to be working and are able to adjust the blend doors...

Have you had the freon level checked by someone with gauges for both high and low sides and who knows how to compensate readings for ambient temperature and for humidity?

The people who have observed this effect usually find the freon charge is low. The freon enters the evaporator on that system on the side where the passenger air goes through. So the expanding freon cools that side of the evaporator but has expanded and absorbed as much heat as soon as it enters the evaporator. Therefore when it gets to the side where the driver's air goes over the metal, the freon has little cooling ability, so the driver gets warmer air or air with more humidity left in it which makes it feel much warmer.

Try on a cooler day, driving at 40 mph and just keep the blower on a low speed setting for the air flow. If lower outside temps and low humidity help the driver's side air feel almost as cool as the passenger side, that would be an anecdotal proof that the freon charge is a factor.

Also, does your car have a cabin air filter? Has it been changed is or it stuffed up with dust and dirt and pollen.

[avisynth]

The cabin air filter is full of dust and leafs. I guess the previous owner never changed it before, since 2000. That is why all of vents are dusty.
I have it changed today.

Originally Posted by imidazol97

Since both actuators seem to be working and are able to adjust the blend doors...

Have you had the freon level checked by someone with gauges for both high and low sides and who knows how to compensate readings for ambient temperature and for humidity?

The people who have observed this effect usually find the freon charge is low. The freon enters the evaporator on that system on the side where the passenger air goes through. So the expanding freon cools that side of the evaporator but has expanded and absorbed as much heat as soon as it enters the evaporator. Therefore when it gets to the side where the driver's air goes over the metal, the freon has little cooling ability, so the driver gets warmer air or air with more humidity left in it which makes it feel much warmer.

Try on a cooler day, driving at 40 mph and just keep the blower on a low speed setting for the air flow. If lower outside temps and low humidity help the driver's side air feel almost as cool as the passenger side, that would be an anecdotal proof that the freon charge is a factor.

Also, does your car have a cabin air filter? Has it been changed is or it stuffed up with dust and dirt and pollen.

[shalopt]

Had same problem, 2003 Buick Century, tried all the various efforts posted.
Found that the Temperature controllers (potentiometers) can be easily broken when removing the knobs. Place sliders at mid range before attempting removal. The bodies are not soldered to the PCB. Some means of appling pressure to the body of the potentiometer helps. The actuators turn 90 degrees (1/4 turn ) the carpeted cardboard under the dash must be removed to view. They are located approximately behind the inner vents a flash light is handy for viewing. There is a slotted shaft about 5/16 diameter towards the outside, watch for movement when the controls are adjusted from max cold to hot. My scanner showed no codes.
Measured temperatures where 18 degrees C passenger side and 23 degrees C driver side. My solutions was low freon after adding 8.7 oz temperatures are 7.5 degrees and 8 degrees with outside air at 83 degrees F. Good luck in your repair. gg

[zachawii]

Everyone with The Manual Buick Dual Climate control heads needs them replaced! I had the same problem with 2003 Century but mine got so bad that it wasn't even activating the compressor so most the time no cold air at all!

It all has to do with the computer chip in the Climate Control Assy.. I also had to replace the Blower motor resistor to get the bottom speeds to work it seems like alot of models were hit with that bad part that burns up the bottom 2 fan settings

[Tech II]

First, Century's do not use the same setup as LeSabres.....

Second, more often than not, the resistor block goes because water hits that hot resistor block, if you have a water leak at the fresh air opening.....

[PrettyInInk87]

I have the same problem on my 02 Buick Lesabre. I was told we I bought it 2 days ago there is a switch I can flip to make both sides blow same temperature is this true if so where is the switch located

[brcidd]

No switch, set them to the same temperature-