Yes they indeed have brake lights...
BEHIND THE BRAKE PEDAL
How do you replace a break light switch on 1995 Chevy Tahoe
either dimmer switch or blown fuse If you are saying that the tail brake lights are working but the third brake light is not....It may be a defective turn signal switch in the steering column.
Start with checking the fuses and bulbs. See sources and related links below for bulb information.
When you open your tailgate...are there 2 screws near the tail-light? homshopper at yahoo dot com.
I have a 97 Tahoe and the brake lights were not working and the problem was in the emergency flasher switch. I just jiggled it and the brake lights worked so am thinking you might have the same problem. It could also be the brake pedal switch located right on the pedal arm.
Fuse for the "Third" Brake LightAlthough I have no experience with the Chevy Tahoe, the systems are similar for almost all vehicles.The third brake light is tied into the wiring for the other brake lights and is protected by the SAME fuse they are.Thus, there is no separate fuse for the third brake light.Therefore, IF your other brake lights are working, then a failure of the third brake light to activate IS NOT caused by a fuse, but instead an "open circuit" condition in the "dedicated" third brakelight wiring [from where its wire "splits" off of the wiring harness to the other brake lights].This is usually caused by a connector which has become disconnected, or a cut or broken wire.
Need to know what the question is.
You may need to check your brake light switch. It is a small switch located on top of your brake peddle (up on the arm of the peddle). This switch allows the brake lights to come on whenever you push the peddle.
A 2002 Chevy Tahoe uses the standard brake fluid in passenger vehicles with power brakes. It is known as DOT3 brake fluid.
You need to CHECK the brake light FUSE with a test light. If the fuse is okay then check the brake light switch. That is just above the steering column under the dash. It is H..L to get to.
use an ohmmeter it will show the ground or a test light if it lights up it willl be the other wire