Break lights only one works both running lights work

[David Baumann]

Trying to fix this issue, any ideas on what’s wrong

[David Baumann]

[David Baumann]

 

[dna9656]

Most likely  you have this: One bulb holds 2 filaments or 2 diodes and the one that glows when you use the brakes is burned out. Buy 2 bulbs and replace them both. if it still doesn't work you got a wiring issue.

[devildog2621]

Had add the same problem. It was the wiring harness. Also there's a panel under the bed that the wire harnesses plug into. I'm sure it's got a name. The connection was corroded and needed to be cleaned.

[redvett]

Brake lights and tail lights are on different circuits check brake light fuses if they are good check the circuit with a tester if dead it probably will be the turn signal switch brake lights go through the turn signal switch.