Tow plug issue.

To make a long story even longer.....It all started when my sister wanted to get rid of her Jetski, the Jetski is irrelavent, it was an easy fix,tear down the motor and rebuild, done.HA Ha. The trailer also needed work, some of the lights desintegrated in my hands while I was checking them, got the light kit and re-wired whole shabang. When it came to wiring for the harness to my wifes 97 Explorer
is when I had an issue. The kit said it was for tail lights, brake lights and turn signals, well when I hook it up to the wires it descibes I get only turn and tail lights no brake lights!! Brake lights are pretty important wouldnt you agree? I have a Chiltons for it but the only way to rig the problem is splicing the wires for the turn and brake light which shorts out the turn signals when braking. I know most auto computers can be finicky so I elected to wire it simple with tail and brake lights for now but I'm sure ther HAS to be a main feed for tail and brake right? The problem is Chiltons diagram didnt help, I got the same issue as above...no brake lights. I was at it until 5 am last night thinking this is too simple, surely I'm over looking something. Are there any Einstiens out there ?!!!! Please dont say give my sister back her Jetski....I might go over board. LOL