Blower works but no air out of vents - broken vacuum line????

[cjlennon623]

Folks,

Good day and thanks for taking the time to read my post. I have a 2002 GMC HD2500 with the 6.0 gas and I can't get the air to come out of the vents in the cab. The blower has all its speeds, you can hear it run but I can't seem to get the air to come out of the vents. I do believe I have a broken vacuum hose leading into the control box for the vents. At least that is how things worked in the old days. If this is true, I have looked all over the firewall and cannot find any vacuum hoses that go through the firewall into the cab. Does anyone know if the HVAC doors are still controlled by vacuum in the 2002 Sierra 2500 HD? If so, any idea where the line is hiding out? I just heard that the HVAC control system for this vehicle may be all electronic. So it comes down to the actual actuator or the control head. Has any one experience in this area? Thank you to all that take the time to read these posts. We really do appreciate you!

 

Chris

[00Silverado4x4]

The controls are electronic now vs vacuum. There is a blender door actuator inside the dash that is either acting up or has gone bad. I do believe it's in the middleish area behind the controls. My truck occasionally does the same thing, I just shut the system off for a few minutes and then turn it back on...worst case I've had to shut the whole truck down for a few minutes and then restart. If you have already tried that you will probably end up having to replace the actuator.

[davester]

Have you looked at/changed the cabin air filter?

[ATMINF]

Also remember these trucks had a " recall"/ service that had the HAVC controls going bad due to humidity buildup. I actually had a similar issue last summer, took the truck into the dealer and they fixed it no charge.

[gmtech4]

Also remember these trucks had a " recall"/ service that had the HAVC controls going bad due to humidity buildup. I actually had a similar issue last summer, took the truck into the dealer and they fixed it no charge.

I doubt they will perform this special policy ( it's NOT a recall) on a 13 yr old truck

 

Op , get alldata.com for $27/yr and research it , you may have a failed mode actuator ,, if the air is not coming out of proper place , a noisey HTR box is a plugged cabin air filter as mentioned , check owners manual for location ,

 

You can scan the HVAC module if nothing makes sence ....

In other words you will have zero fun repairing this concern as a novice backyard handyman

 

I hope it's the filters , do not replace them , just toss them in the bin !!

[ATMINF]

I have to find the letter GM sent me on my truck. It basically said if I had a problem with it bring it in and it would be covered. I just put it in the glove compartment, then last year my AC "went out", granted I knew the AC worked, but the blower was "off". I then remembered the letter and called my local Chevy Dealer they said to bring it in and they were familiar with the issue and they covered it. I just throw it out there because it maybe something that Chevy will cover and not cost a thing. At the end of the day if all it costs is a phone call and some time, it maybe worth it.