I have a 2016 Chevy Express 3500 6.6L Diesel. My van's blower does not turn on with the ***** in any position ... with the one exception that once-in-a-random-while it will turn on weakly with the **** in position 3.

Here is what I have tested so far:

• I started at the blower motor, and applied 12v from the battery. The blower turned on.
• I replaced the resistor module, no change, so I returned that.
• With multimeter, I checked for power from the pigtail that attaches to the blower motor. No power with the **** turned to any position.
• I checked for power at the harness that plugs into the resistor. Only power if I test against the fat red & black wires. No power from the tan, blue, orange, or yellow with the **** set to any position.
• I checked the fuses visually and with a test light - they seem good.

I now have the control module pulled out of the dash and it is sitting on the desk in front of me. I feel like there is more I should be able to test before I just buy a control module to see if that fixes it. But, I am not sure what to test next.

Thanks for any help or suggestions.

 

my blower absolutely quit working in my 07 3500 express. on disassembly, we found some mouse had gotten in and built a nest of junk. and eaten some tasty wires too. replacing the blower was the fix. the wires were a mess --I guess they taste good to mice.

 

Did you test the blower motor relay?

 

no. see Chilton ch 3.10 for procedures in checking wiring in heater/air conditioner control assembly ( the 3 rotary switches on p side dashboard. ) it was easier for me us to start under the hood by examining the blower motor itself. ) complete replacement of the blower motor was cheaper and less work.