Blend Door Coupler

Common symptoms:

A/C blows cold for a bit but then you hear a "thud" sound and your cold A/C is now blowing hot air out of the vents.
When A/C is on and you change the temp control from cold to hot and back to cold, the air doesn't return cold but rather stays hot.

It is possible that it is an issue with the blend door, or in this article's case, the blend door spacer servo. It is a ~$17 part depending on where you get it; Blend Door Spacer Servo p/n 5012923AB.

The steps to replace this little part are simple, but the execution can be frustrating/tricky.

You'll need:

New blend door spacer servo p/n 5012923AB
Right angle phillips head (I actually just used a bit with small pliers, but anything to get in a very small space will do)
Box cutter or sharp knife
Flashlight is also helpful

Procedure:

It is important to note that this procedure assumes that the blend door actuator is working properly.

Firstly, you will need to remove the blend door actuator, which is located on the passenger side under the dash at the transmission hump (techincal term). Getting the blend door actuator out is kind of a pain in the rear. There are two phillips head screws holding it in place. One is super easy to get to and the other is not so easy (well for me at least). I ended up cutting some of the rubber mat and padding away to allow enough room to get in there with a phillips head bit and small pliers A right angle phillips head would've done the job, but I didn't have one around so I used what I had. Once the blend door actuator has been removed from the mounts, you'll need to reach up where the motor was and remove the spacer. Next, simply install the new servo exactly as the other was. This part only goes in one way, so there isn't much margin for error.

Here you can see the culprit; the cracked spacer servo.

Here you can see the blend door motor removed and the mat/foam cut away. That piece sticking up in the middle is where the Servo Spacer sits.

The whole job can take anywhere from ~15-45 minutes depending on how fast you can remove/re-install that second phillips head screw. If both of those screws were easily accessible, the job would take maybe 5 minutes.