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.

 

[TahoeSSer]

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.

Thanks for replying Chip.

I think I was there long enough to feel some heat (15 minutes running the car at full heat). I flipped that black knob(literally of course) countless times and instead of feeling heat coming through the vents, it was cold air. What I did deduce from flipping it was that it would re-route the cold air from the passenger vents above their heads to the big square box just underneath the module, basically into the rear cabin area.

I'll try again tommorrow as I got fed up, exasperated that it wasn't this module but another....hence my post.

Happy New Year All BTW!

 

[chip]

Thanks for replying Chip.

I think I was there long enough to feel some heat (15 minutes running the car at full heat). I flipped that black knob(literally of course) countless times and instead of feeling heat coming through the vents, it was cold air. What I did deduce from flipping it was that it would re-route the cold air from the passenger vents above their heads to the big square box just underneath the module, basically into the rear cabin area.

I'll try again tommorrow as I got fed up, exasperated that it wasn't this module but another....hence my post.

Happy New Year All BTW!

Okay, then that's the door that controls the output of te air flow (hot or cold). We need to find the door that controls the temp. There should only be the 2 I think. If so, the other will be your "Blend Door". Let me know how it goes.......and Happy New Year to you my friends!

 

[TahoeSSer]

Okay, then that's the door that controls the output of te air flow (hot or cold). We need to find the door that controls the temp. There should only be the 2 I think. If so, the other will be your "Blend Door". Let me know how it goes.......and Happy New Year to you my friends!

FIXED IT ! Yeeeeehahhhhhh !

Got lots of hot air blowing in the passenger compartment now.

What I did with the first actuator is shut the vent so it blew only into the rear passenger seats, this tells me that the first actuator/module in line is broken(this is the first and closest to the rear passenger seats). The next actuator/module which is exactly like it, and the 3rd in a series of 4 modules, this one being 3rd of the 4 in line and 2nd closest to the rear hatch door, is the one that does the heat. I pulled off the module, manually turned the black knob the opposite way and "voila", instant heat. I ended up adjusting the metal turn nob on the actuator with gently with a big flat-head screwdriver to align it to the new black knob position so I could fit it back. Three aluminum screws set it back into its position.

Here's the heat culprit pic'd.

Hope this helps everyone in the same position as me.

Here's a link to the part you'll need. RMS Auto is awesome. I used to buy my stuff there for my 95 Impala SS. PART NUMBER is 15-7845 for my 03 Hoe.

http://www.rmsautoparts.com/products.php?cat=134&pg=12

 

[chip]

FIXED IT ! Yeeeeehahhhhhh !

Got lots of hot air blowing in the passenger compartment now.

What I did with the first actuator is shut the vent so it blew only into the rear passenger seats, this tells me that the first actuator/module in line is broken(this is the first and closest to the rear passenger seats). The next actuator/module which is exactly like it, and the 3rd in a series of 4 modules, this one being 3rd of the 4 in line and 2nd closest to the rear hatch door, is the one that does the heat. I pulled off the module, manually turned the black knob the opposite way and "voila", instant heat. I ended up adjusting the metal turn nob on the actuator with gently with a big flat-head screwdriver to align it to the new black knob position so I could fit it back. Three aluminum screws set it back into its position.

Here's the heat culprit pic'd.

Hope this helps everyone in the same position as me.

Here's a link to the part you'll need. RMS Auto is awesome. I used to buy my stuff there for my 95 Impala SS. PART NUMBER is 15-7845 for my 03 Hoe.

http://www.rmsautoparts.com/products.php?cat=134&pg=12

That's awesome! I'm so happy. I can't wait to do this (hopefully today!!!)

Help me clarify some things real quick (see pic). If I take these 3 screws off, will that give me access to the blend door? Also, what did you have to do to get access to all that? How did you get the plastic covers off?


Thanks for all your hard work!!

 

[TahoeSSer]

That's awesome! I'm so happy. I can't wait to do this (hopefully today!!!)

Help me clarify some things real quick (see pic). If I take these 3 screws off, will that give me access to the blend door? Also, what did you have to do to get access to all that? How did you get the plastic covers off?


Thanks for all your hard work!!

To clarify, take the 3 aluminum screws off, you'll see a metal tube built into the module which turns a black plastic knob. With the heat on in the car and rear cabin heat turned on at the front of the car, turn the black knob the opposite way from where it is. You'll feel instant heat coming through the rear vents. When you put the module back, make sure to align the metal tube to the new position you've set with the black knob. Put it back on, but don't plug the wire back on. If the module works intermitantly, it might change it back.

To get to it all, I started to take the plastic cover off the gate in fron of the doors, then the plastic cover where the right rear gate speaker is(note, there is the speaker wire to disconnect), then black turn knob(it's a screw and a holder for carriage net. Once thats done, there is a screw near the front of that panel just behind the right rear passenger seat that has to be unscrewed. Then pull away the panel just beside and to the rear of the right rear passenger seat, you might be able to get away with only need to pop the back half of it off to release the HVAC panel cover. After that, start gently pulling it off(note, there is a wire connecting the rear plug outlet, don't yank it off until you disconnect that wire much like the speaker's wire).

Remember, there are 2 modules to goof around with. The first directs air from rear passenger to rear cabin, the next is the heat/cold, the latter is the one in the pic you replied to and want to fix. I did both, and left the plugs loose so the dampers stayed where I need them to be.

Let me know how it goes.

 

[chip]

Got it fixed last night. Thanks for all your help!

 

[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).

There are two blend doors in the back. One for the temp and one for the vents (ceiling or floor). They are both located behind the trim above the right rear wheel well. Check out this link.

http://www.fullsizechevy.com/forum/...e-rear-air-has-no-heat-just-blowing-cold.html

---------- Post added at 07:40 PM ---------- Previous post was at 07:39 PM ----------

http://www.fullsizechevy.com/forum/...e-rear-air-has-no-heat-just-blowing-cold.html

 

[chip]

Thanks.