help wiring in LED 3rd brake light

hey guys.. last wrecker run that i did I grabbed a roof mounted LED 3rd brake light off an astro van to mount in the back window of my cap ... it's a two wire deal ...

I'm wondering what two wires that I tap into in the mazda tail light harness to get this thing working

thanks

one is a ground...just pull a tail light and probe the wires with someone pumping the breaks when you find the the that blinks with the pumping of the break pedel your set

There should be a brake lite switch located on or near your brake pedal in ur cab.Wire it to that-will be closer than the rear brake lites.BJ

nah hoc, hes mountin it on the window of his topper. -bf

correct... mounting it in the cap.. not the cab. and i tried the wires thing... i'm going to post on the astro site also... maybe there's supposed to be some weird resistor or relay in-line the i don't know about..

Sorry-I thought u were going for the back of the cab.My boo-boo.BJ

Bump.I seem to recall on one of my Maz trying to wire up trailer lites from the taillite harness and I had to buy a special harness just for Maz.May be the same issue for u.BJ