05 Sierra heater/AC problems

Jordanq · July 10, 2016

I apologize if this is already a topic but I searched a few pages and saw nothing related.

My 05 Sierra 1500 is having issues pushing air from my vents, I recently purchased the truck so I don't know exactly how long it has been a issue. I figured it was just the blower motor was clogged or the screens on the intake were covered in crap but that is not the case.

I can feel very little air coming out and it does change between hot and cold fine. I can hear the motor working when I turn the speed up but still the air flow even at max is just a very slight breeze. Like I said before I took out the blower motor and that is clean, looked up at the vent from there and saw nothing blocking, took the windshield wipers and trim off to see the screen for the intake and that was clean as well so I am stumped at this point. Any suggestions would be appreciated.

SunShine01 · July 10, 2016

I had a similar issue with my 05 Z71 Tahoe.

Had to replace the whole dash cluster.

I also had false readings on gas, oil pressure, bolts and a/c regulating thru the face vents, floor mix and defroster.

But mine didn't go hot and cold.

You have an electric issue in the dash more than likely would be my take.

Sent from my iPhone

CapitalTruck · July 10, 2016

Is there are coming out of any outlet? The door actuators crapping out are pretty common on those trucks.

Jordanq · July 10, 2016

Hot and cold is coming out correctly, changes between all the vents like it should. The air flow just doesn't come out differently between low and high. But I can hear the blower motor working harder on high

muddkatt · July 11, 2016

Change the cabin air filter.

arcasey · July 11, 2016

Change the cabin air filter.

^^^^^^^ What he said. If you can switch back and forth between defrost upper vents lower vents and the air flow switches properly then very doubtful there is anything wrong with your doors/actuators. If you have air flowing from all vents including defrost at the same time and are unable to switch back and forth successfully then you may very well have some actuator issues. Chances are your cabin air filter is just stopped up.

CapitalTruck · July 11, 2016

05 didn't have cabin filter...unless added by the owner.

Jordanq · July 11, 2016

Ya I already checked that they discontinued the cabin filter in 02

muddkatt · July 11, 2016

Ya I already checked that they discontinued the cabin filter in 02

Rockauto shows a filter for the 05's.....so i don't know whether it has it or not...Probably not.

Jordanq · July 11, 2016

Unless it is in another place than under the glove box I do not have one.

SpartanAutoworx · July 19, 2016

Is the Blower Motor working on all speeds? If not check the Blower Motor Resister. Also check the wiring at the resister they are common for burning up the pins in the plug which will cause loss of speeds.

If that checks out I would bet money on one of the blend doors going out. If you have access to a tech2 or tech2win you can watch the voltage of the motor to see if its changing.

Jordanq · July 20, 2016

Blower works on all speeds, I hooked it up straight to my battery and it pushes a bit more so that led me to believe maybe a bad resistor or ground. Resistor I see is q aftermarket brand so that is on order to replace. Will look into the blend doors if that does not fix my problem

SpartanAutoworx · July 21, 2016

I would replace the resister and report back with results.

Jordanq · August 6, 2016

The connector that plugs into your resistor and blower motor was the issue. Some how the connector swapped polarities and the fan was spinning in reverse. Cut the clip and put a new one on with butt splices on and we are good to go.