The topic of how to perform the actuator recalibration procedure on Chevrolet , GMC and Cadillac Trucks and SUVs has become an ever increasing topic of discussion.
For manual systems it does not matter where the a/c controls are set but if you feel the need to do something, turn the blower switch on (I prefer speed 3) and set the temperature sliders about .5″ to .75″ from full cold.
For auto systems, press the auto button, with the key on.
Turn the ignition off.
Remove the HVAC/ECAS , 10 amp fuse in the underhood fuse box* or disconnect the battery for one minute.
*Fuse locations can vary from year to year and between different models. Hopefully I will be able to build a list for this.
Install the HVAC fuse or reconnect the battery.
Start the engine. On systems with auto a/c controls the controls will default to 74 degrees F when the ignition is turned back on.
DO NOT TOUCH the a/c controls.
Let the engine run for 1-2 minutes.
Turn the ignition off for at least 10 seconds but no more than 30 seconds.
Restart the engine and then test the a/c controls.
Any chance I could get a reference photo for what I am looking at?
What does the vacuum motor look like? And what do the vacuum hoses look like? 🙂
It is a vacuum actuator and very unlikely that it has failed. As mentioned earlier check your vacuum hoses.
The battery was not replaced. It is weak but still works.
I have determined that the actuator I replaced is the wrong one. I replaced the hot/cold blend actuator. I need to replace the mode actuator for floor/window defrost/dashboard vents.
Any idea where it is?
Your van has vacuum controls for all actuators except the temperature door. I would suggest looking for a broken/disconnected vacuum hose in the battery area. Assuming there was no problem before the battery was replaced. If the battery was not replaced I would look around the passenger side under the hood, where the heater hoses are.
Have a 2006 GMC Savana.
After my battery died one night, the system stopped changing modes. It would only blow cold air out the bottom vent.
Thinking the actuator had gone bad, I changed an actuator on the passenger side underneath the dashboard. I saw it move once, but it hasn’t moved since.
I have followed the steps you outlined here, but it still won’t change modes. Now it also seems to have trouble blowing cold.
I believe this qualifies as a “manual” system. I have three knobs I can turn, for fan speed, temperature, and mode.
1. Disconnected battery for 1 minute
2. Set fan speed to 3, temperature to 60% cold, and mode to off.
3. Turned on vehicle motor for 4 minutes and let idle.
4. Turned vehicle off and removed key for 20 seconds.
5. Turned vehicle back on: no results.
I’m now thinking maybe I replaced the wrong actuator? Is there more than one actuator on the Savana?
Any ideas or suggestions? Thanks