Rear air not cold. Front air is.

[fast_jason]

Hi Everyone,

I got in my Tahoe the other day and turned the rear air on to cool my little guy off. I looked back after a few minutes and he was still sweating. I reached up to adjust the vent to blow on him more and noticed it was warm air. I quickly checked the controls to make sure I didn't have it on heat. The front a/c works great. Any reason the rear air is blowing warm?

Thanks in advance!

 

[07Burb]

A member last fall had this same exact problem and he detailed his fix in a thread. If I can remember who that was I'll track down that thread for you. Give me just a few minutes

---------- Post added at 10:07 AM ---------- Previous post was at 10:04 AM ----------

Here it is not last fall like I thought but

http://tahoeyukonforum.com/forum/showthread.php?t=15787&highlight=blend+door+actuator+calibrate

 

[fast_jason]

Thanks! I will give it a try.

 

[kses123]

I just fixed mine. It was doing the same thing. I had to get a new actuator module for the hot/cold. I also got the updated controller module (computer) for it. It has updated software that prevents it the actuator from over-travelling and ruining itself. It was a quick and easy fix.

See here:
http://www.justanswer.com/uploads/Bluegorilla/2009-02-19_151400_2003-2006_taoe_rear_heat.pdf

 

[Chads93GT]

The other culprit is the expansion valve getting plugged. Ie. trip to a mechanic for a system drain. New valve. Then a recharge. I tested the electronics first. When that failed it left one possibility. Expansion valve. Luckily the part is cheap. Just takes a while to replace.

 

[DenaliAK]

I have the same issue. I replaced the actuator, which was fairly easy, but it did exactly nothing to fix the problem. I'm broke and have other mechanical issues to deal with first, so I haven't had a shop look into it yet.

 

[chip]

I have the same issue as well. I did the actuator, but it looks to be the expansion valve.

 

[kses123]

I have the same issue. I replaced the actuator, which was fairly easy, but it did exactly nothing to fix the problem. I'm broke and have other mechanical issues to deal with first, so I haven't had a shop look into it yet.

Did you replace the control module as well? It prevents it (supposedly) from happening again. See my post above with the link for part numbers.

 

[terrible_buddhist]

I can't say this will work for anyone else as I am fairly convinced this was a coincidence....BUT, I was having the reverse issue (back cold, front hot) I plugged in my scanner...did a code search, nothing came up, and the air started blowing cold again.

 

[kses123]

Yeah, just a coincidence.

 

[DenaliAK]

Did you replace the control module as well? It prevents it (supposedly) from happening again. See my post above with the link for part numbers.

I didn't. At the time, nobody mentioned it. I'll take a look at the link.

Thanks!

 

[kses123]

I didn't. At the time, nobody mentioned it. I'll take a look at the link.

Thanks!

I got the part (15832319) on amazon for like $50 with free shipping!

 

[Joshuasvt]

Subbed for later

 

[AH64Medic]

If you pull the rear passenger panel off to get to the rear HVAC you can rule out the clogged lines and see if its electrical in nature. When you pull the top black housing off (lots of little screws and a bit of a PITA) you will see the rear heater core and evaporator. If the compressor cycles on (refrigerant flowing) then the rear evaporator will get cold. If it is cold then maybe the actuator is holding the blend door to allow the air to go over the heater core and not the evaporator. Its just a flap that diverts the air. Hope this helps.

 

[the blur]

Happened to me. The valve has a screen, that was totally plugged up from leak fix. Too bad you need to recover all the Freon to replace it. And no novice A/C tech can fix it. You need an experienced guy.

 

[Kingfish585]

My issue is the opposite. My dash will blow cold until I set it to max 90 degrees. Gen it gets warm. My rear vents just only blow cold air. It's nice int he summer. It it's getting chilly here now. I figure it's smithing with the blend doors. I've replaced the passenger side one so far