I have a 2007 Silverado Classic and its been an incredibly reliable truck for its 126k miles. But I noticed recently that the heater/AC blower doesn't work in position 3. All other positions work fine, just nothing from position 3.

Is there a relay/fuse/resistor that I need to look at?

Thanks,

RickR90s

 

There is a blower motor resistor which is probably the cause of your problem.

 

Thank You