Low beams not working

1999 GMC SIERRA
149 MILES • 4.8L • V8 • 4WD • AUTOMATIC
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CHILDERS68
  • MEMBER
  • 1 POST
Low beam head light not working in either mode, regular or DRL. I have checked everything that I know but was running tester on the plugs for the bulbs and both terminals are positive is this normal. Bulbs are new, headlight switch, any help is appreciated. Thanks, Greg
Oct 22, 2018 at 10:27 AM
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STRAILER
  • ✓Experienced Mechanic
  • 55,604 POSTS
Hello,

The grounds are connected through the headlight dimmer switch on the column try to cycle the switch many times to try and clean the contacts. Here is a guide to help you check the ground curictur and the headlight wiring diagrams so you can see how the system works.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Check out the diagrams (Below). Please let us know what happens.

Cheers, Ken
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Oct 24, 2018 at 5:10 AM
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