Third brake light hookup

Was wondering if anyone has hooked up an ATA camper shell brake light.
I was told to splice the green/red wire and splice the ground to the white/black at the brake blub. When I did this the brake light did not work.
The shell is on a 1996 Tacoma. It worked on my 89 22re but I got rid of it. The light fixture is a little bit different on the 96. The 22re spliced the green/red but the ground was connected to two of the bulb grounds.
the picture is not my truck but I hooked it up the same way with no luck.
hope the picture comes over.

 

I put some 03 tail lights on my 99 and he had a topper and tapped into the lights at the tail lights. I could pull my light tomorrow and check the wires if you want

 

I just did mine the other day. Same deal, spliced into the green/red wire for hot, and the greyish white one for the ground. Mine works fine... I'm not sure what could be wrong there... good luck though.

 

Yeah I tapped into the tail lights too the drivers side to be exact. There are 4
wires coming from the brake light on the shell rear window. which also houses the dome light, which I don't need, Two red and two black. I tried every combination I could think of but no luck. I will have to pull the plastic off the light just to make sure the bulb is working.

 

attached a wiring diagram that helped me when I did it.

 

I case anyone needs to know the picture is the right way to wire the brake
light. Both of the bulbs in the rear brake fixture were burnt out.