brake lights only working when?

[603 z71]

hey guys got a question, is there a common problem or easy way to fix the headlight switch on these trucks? because my brake light and parking light absolutely do not work when i turn the dial up but when its off they work fine??? i spent all day cleaning the bulb terminals and checking fuses but couldnt figure it out till i tried pressing my brakes on without the lights on.

 

[shelbyt.67]

Check all yer grounds. esp at the front and back lighting harness.

 

[outalne94z71]

rear light ground wire down on the frame at the back is bad, it is backfeeding a ground through the headlight ground