Blend door actuator issue? A/C will blow cold then will go to warm air out all the vents

KEITHSAYLORS1998

MEMBER
2003 CHEVROLET SILVERADO
6.0L
V8
4WD
AUTOMATIC
223,300 MILES

The problem I’m dealing with is my A/C will blow cold then will go to warm air out all the vents. I have the digital duel climate control. A/C is charged no leaks. I did the HVAC reset and it worked great air was coming out at 20 degrees but if I change it heat then back to A/C it’ll work for a bit then go back to warm air. I'm suspecting a bad blend door actuator because I believe there’s a door that passes air over the heater core or evaporate core. Maybe it’s possibly getting stuck in the middle?

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
47,648 POSTS

Since there are two blend door actuators that control that function it would need to be both which would be rare. It sounds more like the control module is bad and it works for a while and then fails which resetting the power reboot the system to be sure we can do a CAN scan which will confirm the issue. Here are two guides and videos to help us see what's going on and I have included the replacement instructions on how to change out the climate control module:

https://www.2carpros.com/articles/replace-blend-door-motor

and

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

The HVAC control module self-calibrates. Check out the diagrams (below). Let us know what happens and please upload pictures or videos of the problem.

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