Side brake lights don't work. Upper light in rear window does work.

Have conflicting info. Haynes shows a shift actuated switch between brake switch and rear lights, I can't locate it.

A service person indicates that the line goes to, and from, the body computer, which is supposedly connected to the fuse/relay panel under the dash.

Which is correct? Where can I find a proper electrical diagram, schematic, and component locations on this vehicle?

Thank you

 

the brake switch is on the brake pedal under the dash
I would check yours bulbs first