Vehicle: 2006 Chevy Express 3500, V8-6.0L, VIN U, Automatic Transmission
Problem: The customer said the heater and air conditioning blower does not work.
Details: With the ignition key in the ON position, the tech verified the HVAC blower motor is not working. Next, he checked the HVAC blower circuits and found the HVAC fuses were not getting battery voltage. He applied 12-volt power to the HVAC fuses controlling the blower and the blower motor ran.
Using the wiring diagram, he traced the power circuit for the HVAC fuses and found that power came directly from the ignition switch. He found the ignition switch feed circuit was open in the run position.
Confirmed Repair: The tech replaced the ignition switch and the HVAC blower ran normally.