Unable to adjust HVAC fan speed

[Corsair152]

Hi, 

 

Recently purchased a used 2014 Silverado LT 5.3L.

Everything has been working great except recently I can no longer adjust the fan speed of my AC.

 

I can still feel air, hot or cold in any vent I select, but it blows on what feels like the minimum setting no matter what. Even if I turn off the fan completely there's still a slight blow to it. The info screen displays that I'm adjusting the fan speed and everything, but nothings actually changing. 

 

Wondering if anyone else had this issue or possibly knows what it could be? Blower motor? Thought I'd check before I took it to a mechanic. 

 

Thanks!

[silveradosid]

you could check the 218 ground connection , it can cause many problems. here the heater schematic

heater.pdf

[davester]

I believe GM is using the same setup for your truck as they used in mine, and for mine, it's not unusual for the resistor pack, and/or the connectors to the resistor pack & the blower motor to fail.  It's possible yours has failed in a way so it always provides a little power to the motor.  Maybe go and unplug and look at the connectors, and take out the resistor pack and look at it for damage, and possibly test that the different connections provide different resistances with an ohmmeter.

[Corsair152]

Thanks for the replies guys. Took me a while to actually get the time to fix this thing. 

 

So I took out the blower motor and had a look at it. Put it back in and it started working perfectly for a little bit. Last night I turned my truck on and the motor was on full blast, even with the dial turned off. I turned my ignition off and it was still blowing. I've unplugged the motor for now, but every time I plug it in, it turns on still regardless of the truck running or not.

 

Would this be a relay? I was told there is no resistor pack for this year and it's just a control module.

 

Any help would be appreciated, thanks!