On my 2014 Chevy Silverado the auto hvac system blows air inside the dash and very little comes out of the vents defroster barely works. Replaced mode blend door motor and control module (the one with the temp dials) but still no success. Recalibrated by scan tool twice but not since control module replacement. Sometimes you can turn off the ignition and it will work properly for a few minutes. Thanks
You mentioned recalibrating with a scan tool. Are there any codes set and can you read data?
It was done at the dealer. Don’t know the codes
I would try switching between fresh air and recirculation to see if any changes are noted. I would also recommend checking the a/c lines to see if they are frosting over under the hood. Near the firewall.
Don’t see any frosting and switching doesn’t change anything still blows inside dash.
You may want to check and see if your truck has a cabin air filter that may be restricted. You stating that it works sometimes should negate that but may be worth looking at.
Testing from this point is best done with a scan tool and experience. About the only thing I can think of that could be do otherwise would be to visually inspect the actuators and doors to see if they respond to commands.
Thanks for the help. It was the cabin air filter. I feel a little dumb but two dealerships and three mechanics didn’t get it right so guess I’ll let that speak for itself. Thanks again !