What do you think it is?

[Conner Fish]

I've been trying to look into something and maybe y'all can help. I have a 2014 Chevy Silverado 1500 LTZ with auto temp control. I'll have the air coming from my vents speed set to low and blowing towards me. But then I switch the direction to defrost and then the blower speed automatically jumps to almost high. I have to turn the knob towards high and then to low for the speed to drop back down to normal. I'm almost think the blower motor, what are other people's thoughts? 

Edited September 14, 2020 by Conner Fish

[m3n00b]

1 hour ago, Conner Fish said:

I've been trying to look into something and maybe y'all can help. I have a 2014 Chevy Silverado 1500 LTZ with auto temp control. I'll have the air coming from my vents speed set to low and blowing towards me. But then I switch the direction to defrost and then the blower speed automatically jumps to almost high. I have to turn the knob towards high and then to low for the speed to drop back down to normal. I'm almost think the blower motor, what are other people's thoughts? 

Sounds normal to me.

[Z45]

Normal, when you set to defrost that turns on the A/C system.  can't run defrost without the A/C, its helps remove moisture from glass