HVAC control screen went dark

REED O. COOLEY

MEMBER
2004 CHEVROLET SUBURBAN
5.3L
V8
4WD
AUTOMATIC
110,000 MILES

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.

Wednesday, March 27th, 2019 AT 8:23 PM

3 Replies

JACOBANDNICKOLAS

MECHANIC
109,885 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.

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Thursday, March 28th, 2019 AT 5:57 PM

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!

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Monday, April 1st, 2019 AT 5:53 PM

JACOBANDNICKOLAS

MECHANIC
109,885 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

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Monday, April 1st, 2019 AT 6:44 PM