HVAC blower stopped working

Tiny
ARUN AMIRTHARAJ
  • MEMBER
  • 2009 HUMMER H3
  • 5.3L
  • V8
  • 4WD
  • AUTOMATIC
  • 200,000 MILES
My vehicle listed above Alpha's HVAC blower stopped working one hot afternoon while running on high for sometime.

Did all usual suspected checks, found the blower resistor connector was burnt, but had been previously repaired by splicing a wire in place of the burnt terminal and solder.
I've replaced the connector and resistor now that I've had it off.

Still no fix. While on the highest setting, can hear the relay buzzing, turning on and off rapidly.
I did remove the blower and connected directly to battery, it works fine.
Another odd thing that happens when trying to turn on the blower, the wiper comes on and sometimes I get "Traction Failed' on the dash.

Not sure if it's related, but I have an issue with my right turn signal as well. Selecting right, turn on the left turn signal. Sometimes its flickers on and off, sometimes it's okay if I choose left then right (but can see the left momentarily flash once even when selecting right).
Sunday, June 13th, 2021 AT 11:00 AM

3 Replies

Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
It sounds like the relay is the issue. If you hear it rapidly clicking then that means it is either shorted or control module (BCM in this case) has a grounding issue causing it to rapidly turn on and off.

A relay should click once when it is turned on and that is it. So I would start with checking voltage at the blower and then remove and jump the relay by applying 12 volts to the 87 terminal.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

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

I attached the wiring diagram below that will help with this.

Please run through this and let us know if you have other questions. Thanks
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Monday, June 14th, 2021 AT 6:40 PM
Tiny
ARUN AMIRTHARAJ
  • MEMBER
  • 4 POSTS
Thank you for the guidance, I managed to trace a bad contact on the ground side leading up to post G106 in the right wheel well. That sorted the blower issue and the wiper/turn signal issues as well.
Thanks again.

Another issue noted when starting, the instrument cluster goes blank while cranking and goes through the startup sequence again after the engine has started. Along with the associated chimes during its start sequence.
Please point me towards troubleshooting this.
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Tuesday, June 15th, 2021 AT 8:07 AM
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
That is great info. A faulty ground strikes again. Unfortunately that is common and commonly overlooked so good job.

As for the other issue let's get a new post started simply so that others can find the solution when they have the same issue.

https://www.2carpros.com/questions/new

We can definitely help with it as I have seen it before. It was a faulty cluster causing one and a PCM the other so we can run through this and try and find out what is happening. If you can get a video of the issue as well that would be great because that will help make sure the expert is on the same page (if I don't get the question) and any other member that visits in the future with this similar issue.

Thanks
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Tuesday, June 15th, 2021 AT 7:39 PM

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