HVAC control screen went dark

2004 CHEVROLET SUBURBAN
110,000 MILES • 5.3L • V8 • 4WD • AUTOMATIC
Avatar
REED O. COOLEY
  • MEMBER
  • 2 POSTS
The HVAC control screen on my Suburban went dark. I have no fan control, no temperature control. The dash lights part of it still works, but unable to see what the settings are, let alone control the AC or the heater.
Mar 27, 2019 at 8:23 PM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.
Advertisement
Avatar
JACOBANDNICKOLAS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 110,190 POSTS
Welcome to 2CarPros.

First, check the 10 amp HVAC fuse in the vehicle's fuse box. Also, check the HVAC ECAS fuse under the hood in the power distribution box. See picture 1.

If they are good, check for power to the HVAC control module behind the center of the dash. Check pins B5 and B7. See picture 2.

Here are a few links you may or may not need. Just adding them in case.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Let me know what you find.
Images (Click to enlarge)
Attached Media
Attached Media
Mar 28, 2019 at 5:57 PM
Advertisement
Avatar
REED O. COOLEY
  • MEMBER
  • 2 POSTS
Fuses were all good, power was there, it wound up being the HVAC control module. I replaced the module, and everything is back to normal! Thanks so much!
Apr 1, 2019 at 5:53 PM
Avatar
JACOBANDNICKOLAS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 110,190 POSTS
Welcome back:

You are very welcome. It can never be something easy and cheap. Regardless, I'm glad you got it working again. Take care of yourself and let us know if you have questions in the future.

Joe
Apr 1, 2019 at 6:44 PM