3rd Brake Light
 

My 3rd Brake light not working all other lights are fine.
Dealer wants $400. to replace,I can get for $140. off the GM parts web site.
Any tips on how to do this would be greatly appreciative.

Mine went out on me as well. Picked up a replacement from the Bay for $60.
I had to remove the back seat, rear lower and upper side panels and finally the rear deck. Pop out the old light and installed the new one. Its a bit of pain in ass. Good luck!

man it would be cheaper to get a ebay zl1 spoiler with the third light and connect it, removing the back seats and deck is super annoying

I noticed when I got my windows tinted in November my 3rd brake light stopped working. Two weeks ago while backing out of the driveway in the dark, I see it's working. It's been fine until today when on the way to work it's out again. I'm not paying to get that fixed nor am I going to start tearing down the interior to get to it.

It was working for a few days, and this morning (2/13) it's out again. Why couldn't the engineers design the light with an access panel from the trunk? Seems so unnecessary to have to remove the entire rear of the interior to get at the stupid light. Luckily there's no problem with the regular brake lights working.

Sometimes it works, sometimes it's dim, sometimes it's out completely.

Mine stopped working today. Muthafker!

Did you ever find the cause of it. Mine was just barely visible and now it is to the point where you cant even see it

Mine has been intermittently working. It's the first sign it's going bad. I bought a new oem for 124$ just need the time to install it.

I've noticed at traffic signals several 5th gens that did not have a working 3rd brake light. These have been on cars since about 1986. You'd think GM would have this down pat by now.