I have a 2003 GMC envoy xl and have been trying to change out the mode door actuator. I live in Montana and cannot use my defrost, foot, or direct fans which is a problem in the winter. However, the rear defrost and fans seemed to work fine. I had it checked by a mechanic and was told the mode door actuator needed to be replaced. Initially, I was sold the wrong actuator and when I installed it would click or bang against the interior paneling. I replaced it with the correct actuator, installed it, recalibrated the A/C system by disconnecting the battery for 1 min before hooking it back up, letting the engine run for 2 min, and turning the engine off again for about 15 sec before turning it on and testing the A/C. It is not banging against the interior paneling anymore but it has also not fixed the problem and I'm still without A/C. I'm wondering if maybe I replaced the wrong actuator since there are 3 inside the front paneling? (If you are looking into the dashboard from under the steering wheel I replaced the actuator furthest to the left towards the back.) Or, maybe the actuator is fine and there is another part that needs to be replaced instead? I would appreciate any answers or suggestions at this point. Thanks

-Jordan

Try a system relearn.
Turn the system on full cold Max AC.
Radio OFF.
Turn ignition OFF.
Pull the HVAC (AC) fuse from interior fuse box. Leave out for 1 minute and replace.
Turn key to run/on position....NOT start.
Do not touch any controls. You'll hear the doors (actuators) being opened and closed. The HVAC module is learning the full open and full close positions. Wait until the system is completely done with the learning process. Less than a minute.
Start and test the system.

Thank you for the info. I tried the system relearn and could hear the rear door opening and closing but nothing from the front mode door. Still no A/C up front. I'm wondering if there are wiring issues that are causing a lapse of power to the actuator? Any suggestions on where to go from here?