Air blowing with vehicle not running

[InspectahDEck]

On my way home the air kicked on full blast on its own. Seems to be blowing out of front windshield defroster. Turning the air off did nothing, just kept on blowing. When I got home and turned off the vehicle it continued to keep running, so I disconnected the battery.

05 yukon, 210k miles

I recorded a quick video

Looking for ideas where to start troubleshooting, I appreciate any help, thanks

 

[Fless]

So this is the HVAC blower? If so, pull the blower fuse in the underhood fusebox. You may have to pull the HVAC control fuse, too.

Then I would suggest inspecting the blower motor resistor (passenger side underdash area); it's a common failure item on these. The wires get hot and melt together, or the resistor fails internally. Be careful when buying a new resistor and make sure you get the same part. Most come with a new pigtail and you'll probably need that.

 

[InspectahDEck]

I tested the resistor and that was the issue. Must of failed internally, wires were fine. Ordered a new resistor and works great, thanks for the help!