This 2003 GMC Envoy came in with the complaint that the a/c will only blow out the defrost and floor. Not through the dash vents. I checked codes and found a code B0263 for a fault with the mode actuator. I first ran into this problem after changing a battery in one of these vehicles last year. Whenever the battery is disconnected the HVAC unit will perform a recalibration of all doors. This causes the door motors to be moved full cycle and the mode door will stick some times. I now hook a jump box to the system before changing the battery in Trailblazers or Envoys to prevent a recalibration from occurring. This way I will not be blamed for a stuck actuator motor.
Anyways to change the actuator motor, first drop the hush panel under the driver’s side of the dash. There are some parts that have to be disconnected from the panel including the turn signal flasher assembly shown in the next picture.
Next, I removed the lower dash knee panel to have a little more room to work.
I had to pull a push pin retainer out at the left side of the duct work in order to remove the driver’s floor vent.
Now, I could finally see the actuator on the side of the heater a/c box.
I removed the actuator and installed the new one. Performed a recalibration with my Tech 2 and put all the panels back in place. A recalibration can be done by disconnecting the battery for at least one minute, reconnect the battery, start the engine and leave the a/c controls alone. I would recommend letting the engine run for at least two minutes, turn the ignition off for at least ten seconds but no more than thirty seconds and then restart the engine so that confirmation of the repair can be done.
I do not recommend connecting the wiring to the actuator until it is installed. They come prepositioned for easier installation.
The notch at the lower edge of the gear is an alignment point. There is a corresponding tab on the door linkage that needs to be lined up with this notch.
To purchase the mode valve actuator, please click here. To see updated information about actuator positions and alignment, please click here.
No, it is not the same part number and at this time I do not know the difference between the two in installation techniques. I would suspect they are very similar to R&R but I have never done one. The part number is 15-73044. I will try to get one in my hands tomorrow to see what the physical differences may be. Please email me at the following address for follow up.
info@the-electric-connection.com
Is this the same part number for a 2002 Envoy with dual climate controls and a inline 6 motor?
Dealer quoted $700 to change this part and I would rater set it on fire than pay those morons.
re: Anonymous rear climate controls not working. I am a dolt. The knob that sets it to rear control was turned to 3. Rarely is there anyone in the back seat so I honestly forgot this was there. I thought I should publicly admit to my stupidity. Thanks again for all of your help. A little “thank you” is coming your way.
Do you have auto or manual controls, front and rear? What is the year make and model of your vehicle? If it is an Envoy or Trailblazer is it an EXT body? Also I have found it better to tackle one issue at a time via email. So let’s focus on the blower problem on the rear system first. Does the rear blower work at all now? Please email me back
at
info@the-electric-connection.com
You may need to copy and paste the address
Excellent tip! This worked like a charm. I was quoted something like $400 for the dealer and did this myself in about 2 hours (I should point out that I haven’t even so much as changed oil in a car in 20 or more years so I’m a total newb). I didn’t have the push pin removal tool for the left side duct but I did manage to do it without it but it would have been significantly easier to have done it with this out. Now I need to find out why my rear vents won’t turn off and can’t be controlled (disclaimer – that started prior to the fix so it is unrelated). Anyway, thanks for the great advice!