HVAC Fan Blower Motor won’t run at all.

ID Status Date Year Make Model Transmission Type A/C Controls Public/Private
#15852 Closed 2003 Chevrolet Suburban public

Checked Fuses, I believe I have an auto system(does have auto setting, included a Picture) removed Motor speed controller, Part number on controller, model number actually, 16250785, serial- 0911. There was quite a bit of paper products from mice activity on part and in housing and up into cabin filter. I have resistance on terminal 1 open on 2 and 3. Resistance is all I measured. I didn’t do the check you showed in your you tube, probably should, but also can I probe the fan directly and check operation with 12 volts? I am
Weak in electrical diagnostics, working on learning more. Thank you for your help.


I had to refamiliarize myself with the system operation for a 2002 year model. It tests basically the same as the later year models and you should be able to perform the voltage tests outlined in the following article. The wire colors are slightly different. The red wire will be orange in your vehicle and the small purple/white wire should be grey/black.

2003 Chevrolet Silverado, Blower

Thank you I will work on those voltage test. But will a continuity test on the speed controller show some possible problems? With purple connected to black from meter, and check for continuity on 3 terminals? If so what kind of resistance would I expect with a healthy speed controller? This is my controller by the way. Having a hard time finding the part, most I pull up don’t look like mine. Thanks.


I don’t have any data to help with a continuity test. I have always done voltage testing and that is all that GM recommends also. The part number is ACDelco 15-8794.  You should be able to do a search for that brand & part number to locate a replacement part.

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