None of the three brake lights work when the brake is applied. The turn signals and the parking lights work. The back up lights work also. I checked the bulbs, they seem to be okay and the fuses are good.
brake lights do not come on when the brake is applied on 2007 Chevrolet Express 1500
I would suggest you check the brake light switch on the brake pedal bracket of your 2007 Chevrolet Express 1500.
i also have the same problem on my 96 silverado, but the third brake light does work. the only light that dont work are the brake lights. Does the turn signal switch have an affect on that or is it leaning more towrads a broken wire?
The turn signal switch could cause the brake light problem you are having. There may also be a "stoplamp" relay in the under hood fuse box that could cause this problem. (Check the fuse box labeling to see if you have this relay.) You will need to check for the proper signal from the brake light switch at the turn signal switch before condemning the turn signal switch.