I have a '91 C1500 Silverado. Blower motor fan works great on HI barely on MID and nothing on LOW. Found blower resistor shorted and replaced (3) relays for AC & HI/LO motor, but still not getting anything in LOW. I feel next step is changing blower motor. Any tips or suggestions and is motor located in the hump before resistor?

 

If you can get to the resistor on the blower motor, then use a multimeter on the + feed to the motor and check the levels of power in all stages(Low Mid High etc.) of the switch. That unit could be bad.

 

I have the old push button circuit board AC/HTR control system. Which electronics work great in a good climate controlled area, not in a vehicle that's in S. Louisiana in mid-Aug. I am able to get to circuit board and do voltage check on entire system. That's the problem w/ this system if my fan button/switch is bad then I have to change out the whole circuit board; dealer item only no aftermarket on this. But, thanks anyway will do all my voltage tests possible before looking at blower motor.