A/C problem
6mo
05-16-2009, 09:37 PM
:confused: I have a 2000 Buick Lesabre,about 60,000 mi. I tried the A/C today and it worked fine on the passenger side vents and rear seat vent. The driver side vent was pushing out heat. Any info on why . thanks maureen
pcmos
05-16-2009, 10:21 PM
First and foremost do you have a LeSabre Limited with digital climate control or do you have a LeSabre Custom with manual climate control?
It makes a difference because the LeSabre Custom doesn't have seperate air temperature mixers for the driver and passenger sides.
In either case you need to determine if you are feeling truly heated air on the driver's side or simply uncooled air.
If you have digital climate control in a LeSabre Limited a lot of people will immediately jump to the conclusion that the driver's side air temperature mix actuator is faulty. This is certainly a likely possibility but the same symptom can occur if the refrigerant charge in the A/C system is low or if the compressor is malfunctioning.
Low refrigerant charge can cause warm air to come out on the driver's side because of the design of the A/C system itself. The system works by expanding the pressurized refigerant in a device that looks like a radiator called the evaporator core. If the regrigerant charge is low or the compressor is not functioning properly then the evaporator core will not reach a consistently cold temperature accross its surface. The refrigerant vapors enter the evap core on the passenger side so that side will end up colder than the driver's side if you are low on refrigerant or if the pressure is insufficient due to a bad compressor. The end result is that the driver's side air will be much warmer than the passenger side.
It's relatively easy and inexpensive to have a technician check the system pressure to make sure that you have a full charge and to rule that out as a possible cause. If the system pressure is sufficient and the compressor is functioning normally then the problem is most likely related to the driver's side air mix actuator. LeSabre Limited with dual climate control provides two seperate mix actuators for the driver and passenger side vents. The actuators are small motors buried in the dash which rotate deflector doors that determine how much of the air will pass over the A/C evap core or the heater core for both the driver and passsenger side vents.
If the computer commands the driver side actuator to position the deflector door to send air over the A/C evap core and it fails to rotate or position itself correctly, the driver side vent temperature will be much higher than the passenger side.
Obviously diagnosing and repairing the climate control system is a lot tougher and more expensive than simply checking the system pressure and compressor condition. You want to rule out the simpler scenario first by paying a qualified A/C technician to verify compressor performance and refrigerant charge. If everything under the hood is working properly and the refrigerant pressure is okay, then you'll be best served taking the car to a Buick Dealership for climate control diagnosis. Replacing climate control actuators can be pretty difficult because of where they are located in the dash.
It makes a difference because the LeSabre Custom doesn't have seperate air temperature mixers for the driver and passenger sides.
In either case you need to determine if you are feeling truly heated air on the driver's side or simply uncooled air.
If you have digital climate control in a LeSabre Limited a lot of people will immediately jump to the conclusion that the driver's side air temperature mix actuator is faulty. This is certainly a likely possibility but the same symptom can occur if the refrigerant charge in the A/C system is low or if the compressor is malfunctioning.
Low refrigerant charge can cause warm air to come out on the driver's side because of the design of the A/C system itself. The system works by expanding the pressurized refigerant in a device that looks like a radiator called the evaporator core. If the regrigerant charge is low or the compressor is not functioning properly then the evaporator core will not reach a consistently cold temperature accross its surface. The refrigerant vapors enter the evap core on the passenger side so that side will end up colder than the driver's side if you are low on refrigerant or if the pressure is insufficient due to a bad compressor. The end result is that the driver's side air will be much warmer than the passenger side.
It's relatively easy and inexpensive to have a technician check the system pressure to make sure that you have a full charge and to rule that out as a possible cause. If the system pressure is sufficient and the compressor is functioning normally then the problem is most likely related to the driver's side air mix actuator. LeSabre Limited with dual climate control provides two seperate mix actuators for the driver and passenger side vents. The actuators are small motors buried in the dash which rotate deflector doors that determine how much of the air will pass over the A/C evap core or the heater core for both the driver and passsenger side vents.
If the computer commands the driver side actuator to position the deflector door to send air over the A/C evap core and it fails to rotate or position itself correctly, the driver side vent temperature will be much higher than the passenger side.
Obviously diagnosing and repairing the climate control system is a lot tougher and more expensive than simply checking the system pressure and compressor condition. You want to rule out the simpler scenario first by paying a qualified A/C technician to verify compressor performance and refrigerant charge. If everything under the hood is working properly and the refrigerant pressure is okay, then you'll be best served taking the car to a Buick Dealership for climate control diagnosis. Replacing climate control actuators can be pretty difficult because of where they are located in the dash.
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