rear ac not blowing - blower motor not working

2003 CHEVROLET TRAILBLAZER
72,000 MILES • 6 CYL • 2WD • AUTOMATIC
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DSTEGALL1
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The rear a/c will not come on using either the front or rear controls. The rear resistor and hvac control module has been replaced. There is 12v on the aux blower motor control line and when checking resistance to ground the fan will come on. I do not see any voltage change on the line using either control knob. Any advice on the next step would be appreciated.
Apr 24, 2011 at 1:43 AM
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MIKE H R
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It sounds like the blower motor relay is not working right but to be sure here is a guide to check the relay and the blower motor wiring diagrams so you can see how it works.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Check to see where you loose power. Check out the diagrams (Below). Please let us know what you find. We are interested to see what it is.
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Jul 23, 2011 at 1:38 PM
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COLOGHUNTER
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Thank you for this post I had this problem and had to get a new blower relay worked great cost me $33.00 I love this site.
Jul 5, 2019 at 6:53 PM
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