Brake lights not working

[Alegabi1]

Hi I have a 2005 Silverado base model singlecab, ever since I got the truck the brake lights haven’t been working (except for the 3rd brake light) I’m going to say it’s not the brake light switch since cruise works and turns off with depressed brake pedal, 4 ways work and light up brake pedal, I never found a single blown fuse in the inside and outside box, when connecting a trailer the brake lights work on the trailer, can anyone help my find the problem?

 

[Formulabruce]

Harness ground at back of truck frame

[carkhz316]

Did you check the bulbs?

[Alegabi1]

I’ll check the ground when I looked at one of the harness I found two cut wires one red and one something else but I don’t see any red wires on the harness, but he’s the bulbs work since the 4 way works

[carkhz316]

The turn signals (hazards/ 4 ways) are separate bulbs from the brake lights.