2015 Tacoma with trailer wiring ripped out, help!

Hi folks, i just purchased a 2015 Tacoma in sweet shape for its age; 4 cyl 5 speed with a mere 100k on it from an estate.sale. It is so fun to drive!!!!! One glitch, that based on what I learn from you experienced folks, I may or may not have to live with. The prior owner used it to haul a tiny travel trailer from "up north" down here to Florida each fall, and then back up again in the spring. (Most of us residents smile & nod gracefully at such people coming down here and leaving their money). Some time before the deceased part taking place and causing the sale (and my eventual good luck), he backed over something (without trailer attached) and completely ripped out the 7 point wiring harness. Me, being the kind of guy who doesnt like to see things broken for long, went from the tag agency straight to the auto parts store and got a new 7 point assembly. I get home, crawl under, and start muttering "WTF" in the two languages I know (similar hand gestures in a third) as I find the wires match no known wiring harness color codes as there was no purple, two whites, and two yellows in addition to the normal rainbow. BUT tucked way up high out of harms way, is also a 4 pin flat female. Sweet, I think and start to unsnarl wiring that would suggest a weedeater mating with aTasmanian Devil, only to find THAT flat 4 isnt even wired into any of the same wires which kinda sorta connected to the obliterated 7 pin! I unsnarl (is that a word?) more of carefully taped up 7 pin wires (it was actually a really nice job) and at some point the bundle of wires connected to the 7 pin literally fall out. Evidently the prior owner had set it up so that he traveled the entire eastern seabord twice a year with just brake lights through the 7 pin!! I unravel more of what i think is the intended 7 pin wiring and get to what looks like factory wiring. but there is just 3 wires, heavy gauge- black, red and white. Im missing 4 or 5, arent I?

Soooo..(and here is the question) how do i somehow use the 4 pIn flat (which i assume to be wired in correctly on its own wiring harness) and those three much heavier wires (which actually went somehow to the destroyed 7pin) to hook up my new 7 pin plug? Yes i know I cant pull much but sometimes the other (monster) truck is in the shop and i have to move my trailer (electric brakes but no auxilliary power) around town. I dont want to use the 4 pin and no brakes. Anyone ever done this? If so, how? Thanks tons in advance!

 

Try asking in the towing or lighting forum . welcome to TW