Brake lights not working properly

2009 CHEVROLET EXPRESS
153,000 MILES • 4.8L • V8 • 2WD • AUTOMATIC
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RICHARD A VERGARA
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  • 1 POST
My brakes lights do not work if the key is not on the on position.
Dec 16, 2017 at 6:47 AM
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PATENTED_REPAIR_PRO
  • ✓ASE Certified Mechanic
  • 1,853 POSTS
  • ASE Certified Mechanic
I do not think they are supposed to work without the key on run, because the "BRK SW" fuse is not hot unless the run/crank relay is energized.
The run/crank relay gets its power from the ignition switch when the key is on only run and start.
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Dec 16, 2017 at 6:59 AM
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