3rd brakelight not working

[362104]

I have a 93 ATX that I picked up a couple weeks ago and the previous owner thought it worked, but it doesn't. Where do I begin troubleshooting this problem.
How often do these burn out?

Thanks, Chip

 

[rubydist]

Unplug the 3rd light and put your multimeter on the connector from the car - is there voltage there when the brake pedal is pressed?

 

[joesho_gb]

First, have a friend stand on the brake pedal when it's dark outside. I know I did some researching on this one, cause mine was the same way. Mine looked so dim that it looked like it wasn't working.
In fact, the LED bar was just burnt.

With the trunk lid open, you be able to see a set of wires running through the trunk, just off center towards the passenger side. Look at the opening next to the trunk latch towards the passenger side. If you follow those two wires a few inches (may go behind the metal, but you can get your fingers in there), there should be a wire harness. That's a good spot to check voltage.