The brake lights turn signals reverse lights all work but the tail lights when you head lights are on do not work.
2003 gmc sierra tail lights not working.
I have changed the bulbs fuses checked the tail light circut board checked the headlight switch.
It could happen due to a loose connection of the wire or the corrosion or damage of the wire ends.
I would second check the fuses probably the best to start especially since its just the rear cause they are probably on the same circuit.
When i checked the wires at the tail light only the wire that worked the turn signals had juice the other 3 did not.
Burnt out light bulbs the other reason your tail lights are not working but your headlights are maybe a blown bulb.
Its got to be a fuse if not i guess it could potentially be a bad relay somewhere in the vehicle.
Electrical is not my strong point so any help would be.
I have changed the bulbs fuses checked the tail light circut board checked the headlight switch.
The brake lights turn signals reverse lights all work but the tail lights when you head lights are on do not work.
When i checked the wires at the tail light only the wire that worked the turn signals had juice the other 3 did not.
If the brake light turns on you have to fix the ground connection.
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In many instances you can see the break in the metal strip of the fuse.
Electrical is not my strong point so any help would be.
When the filament inside the bulb breaks it cannot illuminate the gas enclosed within the glass cover.