2003 trailblazer - no power to hvac

Nov 19, 2003 2 Replies

hi, my wife had our 2003 trailblazer ltz (only 800 miles on it) out on Saturday, and pressed the off button. we had to keep it outside over night, and when we went to use it Sunday there was no display at the hvac display. the fans would not even blow. tried taking the key back out, went inside for 20 minutes and tried again. still no luck. the unit in the center console for the rear had no power either. even the radio was dead. thought maybe a fuse, but all were fine.



like anything else, had appointment for dealership to look at it, and when i started it up... it was working, and i couldn't get it to break again. it had been rainy over the weekend, but drier now. the dealership looked at it but only one "U" code showed up.



i have a 1 year old infant, and it's winter time, so i don't want to play around... anybody else have this problem, or better yet... know the fix.



thanks, john morley


Talk to the dealer... They can call TAC and TAC can tell them to check out the ignition switch... I have changed about 10 so far in the last 2 months for this....real easy to change, and if you want , print this out... If needed I can contact you or the dealer myself... there is no need for them sending you away with this unsolved or repaired...the u code is for loss of comunication with the HVAC module... that's because it had no power and couldn't send a state of health message to the BCM ......Bobo.... P.S. what area are you in????

Check to make sure the plug that goes from the drivers door to the frame is tight. It came loose on my wifes and it caused all kinds of funky stuff to happen.

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