Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
Couple of issues with this.
Could be Blower Motor Relay, Blower Motor Module / Resistor & / or Blower Motor Harness / Plug
You may want to change out the Blower Motor Relay first, then go from there
The Relay is located in the Instrument Panel Relay / Fuse Panel
There is also a TSB for the problem of the Blower Motor Module (see link below)
BLOWER MOTOR MODULE