A/C through Aux vents

[jkssv08tahoe]

Hello everyone I used my A/C in my truck for the first time this year. It blows cold in the front vents. When I hit the Aux button on the dash and have it come out the top vents in the back seat area. It comes out really warm.

Is there a way to make the air come out cold? Does the system need to be charged?

 

[Doubeleive]

you may have a bad blend door actuator in the back, behind the panel on the passenger side, the front/rear heat and AC all run off the same system, although the rear heat does have a small radiator inside the same panel, some times what happens is the rear blend door actuator goes bad or less common the door hinge breaks. but to check it out visually you can take the panel off and watch the hole where the actuator is as you turn the controls and see if it is moving or not. there are plenty of youtube videos on the matter.

 

[jkssv08tahoe]

you may have a bad blend door actuator in the back, behind the panel on the passenger side, the front/rear heat and AC all run off the same system, although the rear heat does have a small radiator inside the same panel, some times what happens is the rear blend door actuator goes bad or less common the door hinge breaks. but to check it out visually you can take the panel off and watch the hole where the actuator is as you turn the controls and see if it is moving or not. there are plenty of youtube videos on the matter.

Thank you I will check that. I didn't think to check the back area. I only feel the hot air coming from the air vents just behind my head. Now I have to check the very rear vents also. Then the blend door.

 

[Doubeleive]

Thank you I will check that. I didn't think to check the back area. I only feel the hot air coming from the air vents just behind my head. Now I have to check the very rear vents also. Then the blend door.

ya the rear roof vents and rear floor vents are fed from the rear compartment unit. there is 2 actuators, possibly 3, one will make it hot/cold, the other up/down or something to that effect. you will be able to tell which is which with a helper turning the controls and then visually watching the actuator. or spend $250 for a knockoff tech2 to tell you same thing, lol, good luck

 

[MD Tahoe 13]

I have a similar issue in my 2013 SSV only I feel no air (heat or A/C) coming out of the rear ceiling vents or the rear floor vents. It blows ice cold (or hot) out of the front vents in the dashboard. Do I have a different problem?

 

[Doubeleive]

I have a similar issue in my 2013 SSV only I feel no air (heat or A/C) coming out of the rear ceiling vents or the rear floor vents. It blows ice cold (or hot) out of the front vents in the dashboard. Do I have a different problem?

sounds like possibly the rear fan is not working it is behind the same panel rear passenger side, you tube videos will show you how to take off the trim pieces to get access they just snap out, you may want to check all your fuses first though before digging into something that might not need to be.

 

[MD Tahoe 13]

sounds like possibly the rear fan is not working it is behind the same panel rear passenger side, you tube videos will show you how to take off the trim pieces to get access they just snap out, you may want to check all your fuses first though before digging into something that might not need to be.

Thanks for the suggestion. I assume this is the 'REAR HVAC Fuse' for the 'Blower Motor Control Module – Auxiliary.' I will give this a try first and then follow up here.

 

[MD Tahoe 13]

Thanks for the suggestion. I assume this is the 'REAR HVAC Fuse' for the 'Blower Motor Control Module – Auxiliary.' I will give this a try first and then follow up here.

Fuse is good. I'll watch a video and see what's what.

 

[Doubeleive]

Fuse is good. I'll watch a video and see what's what.

the fan shouldn't be too hard to pull out or disconnect then you can test it with 12 volts to verify if its dead or not. you can also verify the function of the actuators visualy while you are in there with a helper turning the controls, you should be able to see the spindle turning.