Blower fan will not turn off

80,000 MILES • 5.3L • V8 • 2WD • AUTOMATIC
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JOE WHITEHURST
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  • 1 POST
A/C/heater blower fan runs all the time. A/C works when control knob is engaged. Replaced center control unit but blower fan runs all the time.
Sep 4, 2017 at 10:02 AM
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STRAILER
  • ✓Experienced Mechanic
  • 55,548 POSTS
It sounds like you have a blower motor relay that is stuck on, try to remove it to see if the blower stops.

Here are some diagrams (below) and a guide that will help us fix the problem. The relay is #107 in the last fuse box diagram

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

I included the wiring diagrams for both manual and auto system is case we need to go deeper.

Please let us know what happens so it will help others.

Cheers, Ken
Sep 5, 2017 at 9:16 AM
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