Brake light problem

1997 GMC SUBURBAN
191,000 MILES • 5.7L • V8 • 4WD • AUTOMATIC
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CHARLES R MILES SR.
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there are three brake lights, the one on top of the truck works, but the other two on the sides do not. I have no power coming from the wires. How can I have power to the top brake light but not the others?
Oct 3, 2016 at 4:07 PM
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CARADIODOC
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Without looking at a wiring diagram, I am going to suggest the other two go through the turn signal switch. If they do, the turn signal bulb and brake light bulb are one and the same on the rear. If that is the case and the rear turn signals work, that proves the bulbs and wiring are okay.

If you have access to a good used turn signal switch, try that first. Next, you will need a test light and I will dig up a wiring diagram to figure out where to start.
Oct 3, 2016 at 5:04 PM
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CHARLES R MILES SR.
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Okay, thanks I will try another turn signal switch that I have here and I will let you know.
Oct 3, 2016 at 11:18 PM
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STRAILER
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Hello,

Does the hazards work? It can be the hazard switch as well. Here is the wiring diagrams to help troubleshoot the problem.

Please let us know what you find so it will help others.

Best, Ken
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Oct 4, 2016 at 2:00 PM
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CHARLES R MILES SR.
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Thanks for the advise it ended up being the signal switch because it's a multi function switch
Oct 7, 2016 at 10:08 PM
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CARADIODOC
  • ✓ASE Certified Mechanic
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Dandy. Happy to hear it's solved.
Oct 7, 2016 at 10:18 PM
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