No rear heat

[vmaxaholic]

Greetings! Starting this fall, my wife told me that our '05 Tahoe (5.3l) was not putting out any rear heat. The fan blows and comes out of all the vents, but the air coming out is cool to cold. What the hell could be the problem?? I'm not a mechanical genius, but I'm not a total idiot either. I'm sure I could fix whatever the issue is, but I have no idea where to begin. Any help would be GREATLY appreciated.

 

[corradovrsick]

same problem in mine, hope its nothing to crazy

 

[wade]

blend door actuator.

 

[chip]

I have the same problem. Is there a seperate blend door in the back, or are you talking about the one up front (because that one is working).

 

[corradovrsick]

Do you have to replace the door or is it just stuck? And how to you get to it?

 

[vmaxaholic]

I have the same problem. Is there a seperate blend door in the back, or are you talking about the one up front (because that one is working).

I don't know if there's two blend door actuators, but where is the on located up front??

 

[RedYuk04]

I noticed I had this problem the day after I bought mine, which happened to be in the summer. But the dealer fixed it. There can actually be one of two parts go out or both. The blend door actuator is the cheapest and easiest to get to. You can have someone move the temp knob back and forth while you listen on the passenger side in the rear(towards the middle of the back panel in the cargo area). Turn it on low so you can hear over the blower. Normally you should be able to hear a noise when that door closes to switch to heat. Or you can take the panel off and see if it is moving or not when it should. Pretty easy to replace, 2 or 3 screws and plug it in.

I don't recall if the other part is called a blend door actuator or not. Similar looking part, but seems like the dealership called it something different. It's located in the same area, but more closer to the rear passenger door. More expensive part for some reason. Hope this helps. Sorry no pics, but you should be able to find some, I think its a goes out on everyone at some point.

As a temporary fix, you can move the actuator manually to the heat position since it is winter. That way you at least have heat until you can do a permenant fix.

 

[chip]

I don't know if there's two blend door actuators, but where is the on located up front??

Do a search for it. I know I've seen a DIY thread somewhere on here about it. It had pics and all that. Really good write up.

I noticed I had this problem the day after I bought mine, which happened to be in the summer. But the dealer fixed it. There can actually be one of two parts go out or both. The blend door actuator is the cheapest and easiest to get to. You can have someone move the temp knob back and forth while you listen on the passenger side in the rear(towards the middle of the back panel in the cargo area). Turn it on low so you can hear over the blower. Normally you should be able to hear a noise when that door closes to switch to heat. Or you can take the panel off and see if it is moving or not when it should. Pretty easy to replace, 2 or 3 screws and plug it in.

I don't recall if the other part is called a blend door actuator or not. Similar looking part, but seems like the dealership called it something different. It's located in the same area, but more closer to the rear passenger door. More expensive part for some reason. Hope this helps. Sorry no pics, but you should be able to find some, I think its a goes out on everyone at some point.

As a temporary fix, you can move the actuator manually to the heat position since it is winter. That way you at least have heat until you can do a permenant fix.

This ^^^ is perfect. Thank you so much!

 

[TahoeSSer]

Do a search for it. I know I've seen a DIY thread somewhere on here about it. It had pics and all that. Really good write up.



This ^^^ is perfect. Thank you so much!

I had the same issue with no heat coming into the rear passenger seats and little blowing air. So I took off the panel and found 4 different modules. 2 look identical, 1st and 3rd, while the 2nd and last(closest to passenger door). I took the 1st one off, guess it's call the blend-door actuator, closed shut the louver inside, and voila, air.....however, it's still only blowing cold air. I tried everything up at the front console to get heat to it with the control knobs but "nada". Is there one of the other modules that actually give you the heat?

Pic 1 shows the whole rear hvac unit(the first blend-door actuator is hardly visible to the left of the square box-like module to the left of the pic). Pic 2 shows the 2st actuator(or third module), while pic 3 shows the 4th module(a smaller square box).

Anyone?

We've been pretty fortunate here with almost no snow in Toronto over the past month or so, and recently some mild weather over the past couple of days, so have had time to screw around. It'd be nice to fix it, kids were complaining a few weeks ago when it was freezing cold.

Thanks.

 

[chip]

Great Post! Thanks.

If I'm not mistaken, the blend door should control both hot and cold (hence "blend" - door). Try flipping that door to the opposite side and let me know what happens.