Is there a bulb in the third brake light or fuse that maybe blown this question is 202 gmc envoy?

Yes, there's a bulb in the third brake light of a 2002 GMC Envoy. It's also possible a fuse is blown. To determine which it is, you'll need to:

1. Check the Bulb: Locate the third brake light (usually mounted high on the rear of the vehicle). Access the bulb (often requires removing a cover or panel) and visually inspect it. A burnt-out filament will be obvious.

2. Check the Fuse: Consult your owner's manual to locate the fuse for the third brake light. The manual will show the fuse box location and a diagram indicating which fuse controls the brake lights. Remove the fuse and inspect it. A blown fuse will show a broken filament inside.

If the bulb is good and the fuse is intact, the problem might be more complex and require a professional inspection, possibly involving wiring issues.