For those of you out there experiencing strange AC problems, your problem might be caused by these extremely cheaply made actuators that are apparently guaranteed to fail after about 80,000 miles or sometimes even sooner. The actuators are used for different AC mechanical functions, like switching from hot to cold, changing vents from top to bottom or to activate recirculation. They used plastic gears inside of these actuators and either a tooth breaks off from the main gear or the motor dies quietly.
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Unfortunately GM loves to place multiple of these actuators behind your dash, some easy to get to and others extremely difficult to replace. The part itself is cheap but accessing, testing and replacement is a pain! Look for these symptoms:
1- annoying continuous knocking sound coming from the dash (this means one of the plastic gears have failed and needs replacement)
2- hearing a single knocking noise when you turn on AC or when you turn on the recirculation. (This is most likely caused by recirculation actuator which is behind the glove box, right next to the air bag. This is the hardest one to replace in my opinion)
3- your AC gets cold but not as cold as it should get. (If you don't find a leak in your system, then it could be caused by the actuator that switches from hot to cold or vice-versa. Sometimes with the faulty actuator, it doesn't turn all the to full cold. This one is located on the driver side. See the picture below)
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GM should be ashamed of themselves for engineering these failure points in their design. It is very apparent that the actuators were intentionally designed with a ticking bomb.
![Image]()
![Image]()
![Image]()
Unfortunately GM loves to place multiple of these actuators behind your dash, some easy to get to and others extremely difficult to replace. The part itself is cheap but accessing, testing and replacement is a pain! Look for these symptoms:
1- annoying continuous knocking sound coming from the dash (this means one of the plastic gears have failed and needs replacement)
2- hearing a single knocking noise when you turn on AC or when you turn on the recirculation. (This is most likely caused by recirculation actuator which is behind the glove box, right next to the air bag. This is the hardest one to replace in my opinion)
3- your AC gets cold but not as cold as it should get. (If you don't find a leak in your system, then it could be caused by the actuator that switches from hot to cold or vice-versa. Sometimes with the faulty actuator, it doesn't turn all the to full cold. This one is located on the driver side. See the picture below)
GM should be ashamed of themselves for engineering these failure points in their design. It is very apparent that the actuators were intentionally designed with a ticking bomb.
