Rear heat HELP

[triangle12]

My 01 yukon xl rear heat/ac has not been working for about a year now. I finally got money together to pay for it and no one can seem to fix it. I've had it to 2 different shops (not dealer).
First, lines were flushed and that didn't work. Then the actuator was replaced (shop said it wasn't closing all the way). Still didn't work, so took it back and they flushed again and reset the system. So, $300 later, my rear heat/ac doesn't work. Was told the next step is to replace heater core for $400.
Decided to contact dealer and they asked which actuator was replaced (didn't know there was more than 1). Dealer said not to go straight to replacing heater core because it could be something else.

Any ideas on the problem? are there 2 actuators? Please help.
Thanks

 

[Rivieraracing]

My 01 yukon xl rear heat/ac has not been working for about a year now. I finally got money together to pay for it and no one can seem to fix it. I've had it to 2 different shops (not dealer).
First, lines were flushed and that didn't work. Then the actuator was replaced (shop said it wasn't closing all the way). Still didn't work, so took it back and they flushed again and reset the system. So, $300 later, my rear heat/ac doesn't work. Was told the next step is to replace heater core for $400.
Decided to contact dealer and they asked which actuator was replaced (didn't know there was more than 1). Dealer said not to go straight to replacing heater core because it could be something else.

Any ideas on the problem? are there 2 actuators? Please help.
Thanks

Yeah, there are 2 of them!! So are you only getting cold air? Does the selector knob work, as in can you change the air from coming out of the floor vent to the the overhead air? Do all the speeds work correctly? Just trying to figure out what all works correctly with your rear air!

 

[yukondoit]

I'm having similar issues with my rear heat. I can control the speed and I think the location of where the air comes out, but I get no heat, just cool air.

 

[Rivieraracing]

So, here are a few pics of when I was messing with my rear air components a few months ago, mine is an 02!! The number one is the blend door actuator, it's what changes between floor and ceiling heat for the rear air. The number 2 arrow is the blend door actuator, it's what changes between the hot and cold air for the rear air!! I'd take off that side of interior panels and check to make sure that the number 2 actuator is indeed working at all!! If you look at the second pic carefully, you will see that there are 2 slots within the shiny circle in the middle of the actuator that when the actuator is working, you can tell if that circle is spinning!! Just have someone change the heat selector knob while you are looking at the actuator to see if it's moving at all!!
Hope the pics help!

 

[Rivieraracing]

Also, if you don't want to take off the paneling, put your ear up to the interior paneling at the approx spot where the actuator is and have someone change the hot/cold selector knob from hot to cold and see if you even hear it moving (I think the fan has to be on for them to move but don't remember exactly, just have the fan at 1 or lowest speed). If you can't hear the blend door one (#2), then go to the #1 actuator and see if you can hear it!! If you can hear the #1 and not the #2, you are probably gonna have to pull the interior panel and confirm the movement visually, can also check for proper electrical connections at the time as well!!
You should be able to hear them move if you are next to them!!

 

[triangle12]

rear heat

Great Pics! The air is blowing luke warm no matter what temp. you turn the knob to and the colder it gets outside, the cooler it seems to blow. AC doesn't get cold in the back and heat doesn't get real warm. I have only checked temp. out of overhead, I just assumed the rear floor vents were doing the same thing. All fan speeds work great. Guess I need to see if floor/overhead selector works. When you say to change the heat selector knob when checking the actuator, do you mean turning the temp knob from cold to hot?? Did you have to reset anything after replacing the actuator?
Guess I could also call the shop to see which one they replaced

---------- Post added at 12:51 PM ---------- Previous post was at 12:25 PM ----------

called shop and the guy who worked on it wasn't there today. Looked over my paperwork and it says TEMP DOOR MOTOR replaced. Would that be the #2actuator in your pic?

 

[Rivieraracing]

Great Pics! The air is blowing luke warm no matter what temp. you turn the knob to and the colder it gets outside, the cooler it seems to blow. AC doesn't get cold in the back and heat doesn't get real warm. I have only checked temp. out of overhead, I just assumed the rear floor vents were doing the same thing. All fan speeds work great. Guess I need to see if floor/overhead selector works. When you say to change the heat selector knob when checking the actuator, do you mean turning the temp knob from cold to hot?? Did you have to reset anything after replacing the actuator?
Guess I could also call the shop to see which one they replaced

---------- Post added at 12:51 PM ---------- Previous post was at 12:25 PM ----------

called shop and the guy who worked on it wasn't there today. Looked over my paperwork and it says TEMP DOOR MOTOR replaced. Would that be the #2actuator in your pic?

Yeah, turn the knob on the overhead rear heat console from hot to cold temp while listening/looking at the actuator and you should hear it move and see the round silver circle move!! I didn't replace any actuator on mine, I was just seeing how everything worked and also to make sure it was working correctly, which it was!! I think there is a relearn process that you need to go through when replacing an actuator, but can't remember what it is off hand!!
And yes, if they said that they replaced the temp door motor, then it would indeed be #2 in my pic!

 

[triangle12]

rear heat

any hints on removing the side panel?

 

[Rivieraracing]

Shoot man, it's crazy the stuff you have to pop off, some bolts, nuts, some trim pops off!! Give me a bit today, I'll look back in my book and if it's a page or 2, I'll try to scan it off and post it up for you!
Pm me if you haven't heard back from me by tomorrow, I may forget!

 

[triangle12]

rear heat

thanks for all your help!!

 

[yukondoit]

I'm going to do this. I remember back in November I was sitting in the middle row and I heard a noise coming from the rear, it was coming from the ceiling. It sounded mechanical, like it trying to do something. Then it died, like it ran out of juice. haha...

 

[triangle12]

rear heat

Rivieraracing- thanks to you, I was able to fix the rear heat today. after lookin at your pics i was able to take off the panel and see that the #2 actuator they put in didn't work. i took it back to them and told them it was bad. after 2hrs of waiting and them trying 2 different actuators, they finally decide to replace the part with an ACDelco brand and it works fine now.
What ticks me off the most is I had to figure out what was wrong. they said yesterday that they checked the actuator and it was working, so the next step was to put in a heater core. Obviously, they didn't check it and all i got today was "we won't charge you for putting in this more expensive part". i'm thinkin "WOW, thats tough to put on after i had taken everything after". Oh, i also had to put everything back together and they broke my window rain guard when they opened the door into the lift.

anyway, thanks again! i owe ya!!!

 

[Rivieraracing]

Rivieraracing- thanks to you, I was able to fix the rear heat today. after lookin at your pics i was able to take off the panel and see that the #2 actuator they put in didn't work. i took it back to them and told them it was bad. after 2hrs of waiting and them trying 2 different actuators, they finally decide to replace the part with an ACDelco brand and it works fine now.
What ticks me off the most is I had to figure out what was wrong. they said yesterday that they checked the actuator and it was working, so the next step was to put in a heater core. Obviously, they didn't check it and all i got today was "we won't charge you for putting in this more expensive part". i'm thinkin "WOW, thats tough to put on after i had taken everything after". Oh, i also had to put everything back together and they broke my window rain guard when they opened the door into the lift.

anyway, thanks again! i owe ya!!!

Glad to hear you got it fixed, but if they broke something in the process while fixing it like it should have been fix originally, then I'd be going back and making then fix and make that right!! It's not really hard to figure out what all needs to be taken off to remove that interior panel, just sometimes hard to figure out if something has a hidden screw or that it just needs to be pulled on hard enough!!

I'm going to post up the 3 pages that I scanned and followed out of my Haynes manual, if this is wrong to do on this forum, could a mod please remove them and let me know!! Thanks!!