How to fix Hot Air when A/C is on. Install new air mix/blend door actuator

[jesse13]

After having my battery unplugged for about a week the blend doors would not switch from defrost to vent. I used the relearn method that op posted and BOOOMMM!!! It fixed the problem. Thanks OP

 

[SLCHOE]

You need to find out which one it is. You need to test out each door.

Temperature Blend door: Does the air switch from cold to hot?
Floor/Vent door: Can you switch from windshield to vents to floor?
Recirculation door: If the above two are working properly, this is probably the culprit. This door switches from directing cabin air or fresh outside air into the blower intake. While switching you should be able to hear a difference in air volume as it changes.

Well I finally installed the Blend door actuator from Dorman. And it was a pretty simple straight forward. Did the calibration after installation and now the A/C and heater function works again like it used to. Thx TYF members for all your help!

Hi All
Changed The blend door actuator. under the Glove Compartment Still blowing heat out
Of the passenger side. Now after reading for several hours I have found out I changed the Drivers side actuator. I guess it is OK as the drivers side acts up rarely but does act up.
Other problems noted and learned.
1 The rear unit now only blows cold. Looks like the rear AC controller mounted on the
rear Blower case is the problem. one with the Red / Gray connectors
2 The front AC control head "when it is cold out" when you set the temp from cool to
warmer the temp readout will go up one or two degrees and then down a few degrees
when it warms up works correctly most of the time.

All in all I really like the truck the manacles have been great But the Electrons SUCK lately.
The truck is coming up on 190 thousand miles other then service work it has been good.
Some of the repairs I have done
Had Coolant leak at water pump " Bad Gasket " changed gasket, thermostat, water pump
and all hoses $$$ While we were in this deep Replaced Bad "wet" Knock sensors When all
back together would not turn over. Replaced Starter. Started right up. This was all at 180k
Factory Brakes went 175K still had some pad left.
Changed Alternator 150K
Rebuilt Dash Gage Cluster 145K
Last Week end The Tailgate window Hinge came louse from the Glass Can not be re-glued
will need a new window !@@## $$$
All in all it is still cheeper then a car note. I have learned a lot from these forums but all the answers are not correct. So read read and read some more. You will get the correct answer
if you keep looking.
Also THANK You to all that try to help each other together we can fix most things
Michael

1) rear HVAC module

2) The main control head is bad. Mine does the same thing but I live with it until I can find one out of a parts truck for free. The pots in them are crap and fail. I have to push on the knobs for mine while I turn them to get the to work and even now that's starting to not work. I know what it is but I'll deal with it. Up here in Utah, you have 2 HVAC settings. In the summer, super cold. In the winter, super hot.

 

[regguay]

I was having same issue with our Yukon on and off for past few years until finally was blowing only cold air at the rear during the winter then had to fix it. Another post showed that the actuator could be taken apart and repaired and that is what I did. There is a metal contact inside with little brush like contacts and it seems they get contaminated with grease over time which is used to lube the gears inside and must break the ability to conduct current. I just bent the little metal brushes back a little to make sure they are making contact, cleaned the electrical contact surface where they contact together and worked fine ever since. did same to the front actuator door because it was acting up sometimes. Just mark the actuator and the housing location with a marker before taking apart the actuator assembly so you put it back together the same or you will have problems lining up the actuator with the heater door knob that it has to align up with. Easy fix.

 

[STL_Denali]

I had an issue with the Rear vents only blowing cold last November. Replaced the Control Module (15-73506 ) and fixed the issue. Now yesterday turning on the Rear AC (after its been working all summer) its blowing hot. Hard to tell if its heater hot or just hot since its 100 degrees out. I wouldn’t think the control module would go bad after 8 months or so….

 

[mallarddede]

I have a similar problem...front A/C works GREAT...but only hot air to the rear. Both Rear Actuators are working properly as I visually tested them without interior panel on. I am NOT getting cold air to the rear at all....any ideas? My vehicle is a 2000 GMC Yukon

 

[Greg W]

I have an '05 Yukon Denali with dual climate control. Recently replaced the driver side blend door actuator and fixed the driver side hot air problem. Now the HVAC on both sides blows cold when set all the way to 89. At 90 they both transition to hot. Go back to 89 and both sides transition to cold. This happens whether outside temp is 70F or 105F. If I set both sides to 89 then move one side to 90, that side blows hot and the other side stays cold. Works same way either side. In auto mode it's blowing out the dash vents, but I can also switch between floor, dash and defrost vents and the same thing happens - 89 blows cold, 90 blows hot. I tried an Autozone remanufactured climate controller but everything still acted the same. I've gone through the reprogram procedure a bunch of times.

Suggestions?

 

[heater_up_c]

I have an '05 Yukon Denali with dual climate control. Recently replaced the driver side blend door actuator and fixed the driver side hot air problem. Now the HVAC on both sides blows cold when set all the way to 89. At 90 they both transition to hot. Go back to 89 and both sides transition to cold. This happens whether outside temp is 70F or 105F. If I set both sides to 89 then move one side to 90, that side blows hot and the other side stays cold. Works same way either side. In auto mode it's blowing out the dash vents, but I can also switch between floor, dash and defrost vents and the same thing happens - 89 blows cold, 90 blows hot. I tried an Autozone remanufactured climate controller but everything still acted the same. I've gone through the reprogram procedure a bunch of times.

Suggestions?

Had this problem myself. Previous owner cut the wires to the Cabin Air Temperature Sensor Aspirator. It is right above the driver seat looks like it might be a little speaker or mic for on star. Once I reattached the wires and started the truck, the sensor was making a pretty annoying buzzing sound. Replaced sensor now I have temp control again. Hope this helps.

 

[vjr021]

This sounds crazy, but it works... a temporary fix for this is to turn the truck off and cycle the ignition three times... when you restart it, the system will reset and it will work fine (until it does it again)... I do it about once a week...

 

[jough]

My driver side actuator switches from AC to heat randomly. However, just restarting it resets the actuator. I don't need to cycle the key 3x on my 2004.

 

[darth_burban]

Hey guys I got a 2000 suburban, I have lukewarm heat on the hot setting. I attempted recalibration and that failed. I took a look at the actuator and found it wasn't plugged in. Plugged it in, same ill effect. Heater hoses are getting warm, radiator hoses as well. Truck stays at 198-200*. Truck has a fresh head gasket, with green universal coolant. I flushed the old coolant out, which was green as well... Is it heater core? Rear heat is the same way...