[SOLVED] Weird HVAC issue after battery replacement

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

cooki3mnster

Full Access Member
Joined
May 24, 2021
Posts
114
Reaction score
168
I recently had to replace my washer fluid bottle and battery. After I replaced the battery my wife drove the truck to work. When she got home the Drivers side vents were blowing hot air and the pass was blowing cold. After a quick search I tried this recalibration method:

  1. Clear all DTCs.
  2. Place the ignition switch to the OFF position.
  3. Install the HVAC actuator.
  4. Connect all previously disconnected components.
  5. Remove the HVAC/ECAS fuse for a minimum of 10 seconds.
  6. Install the HVAC/ECAS fuse.
  7. Start the vehicle.
  8. Wait 40 seconds for the HVAC control module to self-calibrate.
  9. Verify that no DTCs have set as current DTCs.

Now the drivers side blows cold air and the pass side blows hot. When pressing the mode button it will change from dash vents to defrost, to footwell but I cant get the temp to change. I've already called the local parts house and ordered some actuators. Is there anything I can check before I start taking the dash apart to replace them? I feel like if the actuators had failed they wouldn't have moved after the calibration. Or maybe I'm over thinking.

EDIT: This is a 2005 Yukon XL with digital controls and Rear Aux A/C.
 

Trey Hardy

8” fabtech icon coilovers uniballs 24x14on35/15.50
Joined
Jun 12, 2020
Posts
2,090
Reaction score
5,206
Location
Eastern North Carolina
You can try taking both battery terminals and holding them together while there disconnected from the battery to reset all the systems along with the fuse under the hood and run it through the calibration steps for the hvac temp door actuators
 

Trey Hardy

8” fabtech icon coilovers uniballs 24x14on35/15.50
Joined
Jun 12, 2020
Posts
2,090
Reaction score
5,206
Location
Eastern North Carolina
My Tahoe anytime it goes dead or you disconnect the battery it does the same thing one side is cold one side is hot usually the driver side is hot and sometimes the rear vents will blow hot oddly I drive it some and it usually fixes its self once I park and restart the car but mines a 07
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
23,630
Reaction score
34,482
Location
Stockton, Ca.
unhook the battery ground, hook it back up, turn the key to run (not start) let it sit 30 seconds or so (time to let it self-calibrate) then start it up and see if it goes back to normal.
when you do this you should be able to hear the actuators moving around if you listen carefully, some people are not tuned into there vehicles......
 
OP
OP
cooki3mnster

cooki3mnster

Full Access Member
Joined
May 24, 2021
Posts
114
Reaction score
168
Thanks for the input guys, I'll give it a try tonight and see what happens.
 
OP
OP
cooki3mnster

cooki3mnster

Full Access Member
Joined
May 24, 2021
Posts
114
Reaction score
168
Who do you know with a Tech-2 or equivalent?
The only person I know that would have one moved to New Zealand earlier this year. I've been thinking about pulling the trigger on one and this might be the push I need. chinacardiags has one listed for $269 right now
 

George B

¯\_(ツ)_/¯
Joined
Feb 5, 2020
Posts
7,632
Reaction score
18,084
Location
Oconomowoc, Wisconsin 53066
The only person I know that would have one moved to New Zealand earlier this year. I've been thinking about pulling the trigger on one and this might be the push I need. chinacardiags has one listed for $269 right now
Where are you located? We have a few members spread over the US.
 
OP
OP
cooki3mnster

cooki3mnster

Full Access Member
Joined
May 24, 2021
Posts
114
Reaction score
168
Where are you located? We have a few members spread over the US.
NorCal - about 50 miles east of SF in Livermore.
 

Forum statistics

Threads
129,070
Posts
1,809,868
Members
92,134
Latest member
KCW_Andrew
Top