Rear hvac problem on my 03 Yukon?

[Vincesrg03]

Hello everyone I am new to the forum, but have come to the site many a time for help fixing my Yukon. Hope someone can help me out before i gotta dish out some cash to a mechanic or (gulp) the dealer. I have an 03 Yukon SLT with rear heat and ac. Only cold air was blowing out the vents, so i went on the forum and saw that alot of people were having the same issues. Many said to replace the blend door actuator. I removed the panels and checked the actuators. The one that controls the vents worked fine, but the one that controls the temp seemed stuck. So i removed it and replaced it. It seemed to work when i first installed it, then it did the same thing and went to cold only. I removed the vent actuator and put the new one i bought on and it worked fine on there, also put the original temp actuator on the vent door and it also worked fine. Could it be a sensor or the control panel. Checked all the wiring and probed it and it looks good. Its cold up here in Illinois so for now i left it on heat. Could really use some help on this. Thanks

 

[hefe510]

My 03 Yukon SLT had the exact problem and i read the same thing. I actually replaced the rear control module. Changed it out last week and so far so good. I've had rear heat for a week, before i couldnt get a lick of hot air.

 

[Vincesrg03]

Thanks for the help. Cold as f!@# in Illinois. Maybe i will wait till the weather warms up to check it out. Can you tell me where it is located and how much you paid for it?

 

[04YUKON]

I had the same issues with my 04 yukon....I replaced everything In the back of the truck with no luck...
my fix.
1st check the actuator and see if thats yer prob... sounds like it is....u can test it is by switching the temp control to about half just to about be safe... pull the actuator off from the floor roof control. Exact same part. Plug it into the heat/cool part of the wiring harness.
Adjust yer heat controls and see if it gear moves.
if it does.its not the pack that the other guy mentioned. Which is that main box in the back with the two plugs. One red one blue I think?
Anyways plug the other actuator into the floor /roof plug... see if tge gear moves. ..
if still no. And you dont want to drop another 85+ bucks to chevy......
you can very carefully open up the actuator. ....
slide. Out the main gear... its super simple once you see inside the actuator. ..
plug it in while its in your hand gear out and cover off... see if it starts spinnig the other gears...the part you want to be careful with is the part that turns the door. Its the main switch and the problem. It tries to open the door so far it over shoots its power point and freezes... again you will see it once its open ...

What I did.... was put the actuator back onto the tuck screwed it dn and all...and hooked it all up like it should be.........
except
leave that one big gear and the cover off so u can adjust yer the switch....
make sure the heat switch and the door are in the same position ...all the way hot or cold...max...and gently turn the rotating piece until the gears stop spinning this will see be yer end point..... now slide in the big gear and snap the cover back on.... should be good to go... I took mine into to have to have them diagnose it again. ... the hooked up their scan tool and said it was working fine. But there was a code. They cleared it but I havehad no new issues with the rear heat since... and didnt pay the dealer a thing... call orr text if you like...for. more Info clarification. ...904_361_8800. Scott

---------- Post added at 01:43 AM ---------- Previous post was at 01:41 AM ----------

I had the same issues with my 04 yukon....I replaced everything In the back of the truck with no luck...
my fix.
1st check the actuator and see if thats yer prob... sounds like it is....u can test it is by switching the temp control to about half just to about be safe... pull the actuator off from the floor roof control. Exact same part. Plug it into the heat/cool part of the wiring harness.
Adjust yer heat controls and see if it gear moves.
if it does.its not the pack that the other guy mentioned. Which is that main box in the back with the two plugs. One red one blue I think?
Anyways plug the other actuator into the floor /roof plug... see if tge gear moves. ..
if still no. And you dont want to drop another 85+ bucks to chevy......
you can very carefully open up the actuator. ....
slide. Out the main gear... its super simple once you see inside the actuator. ..
plug it in while its in your hand gear out and cover off... see if it starts spinnig the other gears...the part you want to be careful with is the part that turns the door. Its the main switch and the problem. It tries to open the door so far it over shoots its power point and freezes... again you will see it once its open ...

What I did.... was put the actuator back onto the tuck screwed it dn and all...and hooked it all up like it should be.........
except
leave that one big gear and the cover off so u can adjust yer the switch....
make sure the heat switch and the door are in the same position ...all the way hot or cold...max...and gently turn the rotating piece until the gears stop spinning this will see be yer end point..... now slide in the big gear and snap the cover back on.... should be good to go... I took mine into to have to have them diagnose it again. ... the hooked up their scan tool and said it was working fine. But there was a code. They cleared it but I havehad no new issues with the rear heat since... and didnt pay the dealer a thing... call orr text if you like...for. more Info clarification. ...904_361_8800. Scott

 

[Vincesrg03]

Thanks for the info Scott. Sorry i haven't responded sooner, but busy with work and holidays. When i first was checking the actuator, I did pull off the cover and noticed the gear spinning. I didn't know i could fix it there. For now i wil leave it as is,since its cold here. Soon as spring comes around i will try your fix. Thanks.