AC not working right

[Keith.B.Nimble]

Before I begin I just want to state that I used the search function but I have found the results confusing so I figured I would start a new thread.

When I turn on the AC in the car it blows fine on the passanger side. However on the drivers side the air is always hot and with very little pressure. I can adjust the air to different locations (feet, window, etc) but its hot and with little pressure.

I have checked the refrigerant pressure using one of those cheapy gauges from Autozone that is attached to their refill cans. The readings were good so no refrigerant was needed.

I am guessing I have a bad actuator but I don't understand why the airflow is low. My 2002 doesn't have a cabin filter and I would figure that would effect the passanger side too.

Keith

 

[littleblazer]

If you move the passenger side to heat, is the flow greatly reduced as well? I know in my truck 3 on air is like 4 or 5 on heat.

 

[Mooseman]

Heat setting greatly reduces air flow on either side. The problem on your driver side is likely the hot/cold air blend on the driver side. Try to reset the system by pulling the HVAC-B fuse for 30 seconds. After putting the fuse back, turn the key to run but don't start the engine. Let it do its thing for a couple of minutes and then try it out. If it's still just blowing hot, then the actuator had failed.

 

[Keith.B.Nimble]

Heat setting greatly reduces air flow on either side. The problem on your driver side is likely the hot/cold air blend on the driver side. Try to reset the system by pulling the HVAC-B fuse for 30 seconds. After putting the fuse back, turn the key to run but don't start the engine. Let it do its thing for a couple of minutes and then try it out. If it's still just blowing hot, then the actuator had failed.

I brought my trailblazer to work today. I will test it out during lunch and report back.

Is there a link for replacing the blend on the drivers side available? Just in case that is what it turns out to be.

Keith

 

[Keith.B.Nimble]

Mooseman

You are correct. The airflow is much lower when in the heat setting.

Here is something interesting. When I turned on the AC to check on that, the AC was blowing fine. It had good pressure and it was blowing cold air. I turned it to the heat setting and it worked as it should. Turning it back to cold and it worked again.

The only thing I can think of is last weekend I replaced my CPAS. Part of the procedure is to remove the serpentine belt. In order to do that safely I disconnected the negative battery terminal. The job took a total of 45 minutes or so. That must have caused a recalibration of the front acutators.

So at least for now my AC is working properly.

Keith

 

[Mooseman]

That could be it if you touched a control for the HVAC (i.e. turned it off) while it was calibrating and it got screwed up. Glad it turned out OK.