Tail Light Issue

[First66]

I recently bought a set of tail lights from Classicparts.com and my wiring is off and I dont know where to start. I searched the Electrical section of the forum but most, if not all threads are of post 67 trucks so I figured someone here might be more familiar with the problem.

http://www.classicparts.com/1960-66-...ctinfo/49-132/

Turns signal function is the only one that works. When I pull the headlight switch, nothing, and when I brake, nothing. The new tail lights have an orange and black wire, and my truck has a four wires going back, all the same color. I used a spark tester to tell the Left and Right signal wires, but got nothing from the other two. Other than follow the faulty wires up to the cab, what else could it be?