Need help with a/c problems after unhooking battery

Jennd5184

Original poster
Member
Mar 28, 2013
2
Hi everyone! I currently own a 2003 Chevrolet Trailblazer LT EXT. So far I've loved it, but recently every once in a while, when I'm at an idle, it's rough and acts like it wants to stall, but it revs back up. Then tonight, my husband was installing headrests with the dvd players, and of course had to unhook the battery. I've read on other threads that they have the same problem, but I just want to make sure it's all connected to him undoing the battery. Now, the a/c doesn't work on the driver's side but works just fine on the passenger, and there's the lovely knocking noise in the right rear interior quarter panel. I've read that the actuator in the back can go out when the battery is unhooked, but I'm just wondering if that would also cause the actuator in the front to go out also? And when the a/c is turned on, the car idles really rough, and again acts like it's going to stall, but it's almost continuous. Most of this is just now happening after he worked on it, but it was doing the almost stalling before, but not nearly as often. Could the stalling have been from a dirty throttlebody but gotten worse after he unhooked the battery? Of course he's not too happy since he didn't necessarily need to unhook the battery, but did as a safety precaution and now things have gotten worse. Thanks in advance!
 

neelskit

Member
Dec 7, 2011
69
Running rough when the A/C is on is most likely due to a dirty throttle body. Disconnect the battery again and clean the throttle body- instructions in the "FAQ" section.

I had the exact same problem with the HVAC actuators you described last week when my battery went dead. Luckily, when I disconnected the battery again, they re-calibrated correctly and everything worked. Hopefully you will be as lucky as I was. If not, you will need to replace the actuators that failed.
 

Blckshdw

Moderator
Nov 20, 2011
10,685
Tampa Bay Area, FL
neelskit said:
Luckily, when I disconnected the battery again, they re-calibrated correctly and everything worked. Hopefully you will be as lucky as I was. If not, you will need to replace the actuators that failed.

If you go for the recalibration, (you can also do this by pulling the HVAC fuses in the fuse block under the 2nd row driver's side seat) make sure the system is turned off, and don't touch any of the controls for about a minute, until the calibration is complete. If you turn your key to ON, without starting the engine, you will be able to hear them going through their cycles :twocents:
 

RayVoy

Member
Nov 20, 2011
939
Just to add to what the other guys are saying, I've had to disconnect 3, 4 times to reset the actuators. The good news, mine have always reset.
 

Jennd5184

Original poster
Member
Mar 28, 2013
2
Thanks everyone for your replies! As of right now, it is still rough idling with the a/c on, and the front driver's side a/c is not working, but good news is, the back stopped knocking. Hopefully we will get the throttle body cleaned this weekend, and *fingers crossed* once we unhook the battery to do that, I'm hoping the actuators will recalibrate. We'll see. Thanks again!
 

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