2015 wiring question and detailed wiring diagram

I'm new to TW and need some electrical help. (Did I post this question in the correct place and form?)

Just bought my 2015 Tacoma 4x4 and discovered a puzzling wiring issue that concerns me. Under the dash near the fuse block there is a bundle of 4 wires in what looks like part of the OEM harness that has been modified or tampered with by a previous owner. It includes 3 heavy wires, maybe 14 or 12 gauge and 1 small wire, maybe 18 gauge. The larger ones are red, black, and black with red tracer. The small one is green with white tracer.

This wrapped bundle of wires comes from a plug/socket combination up high under the dash on the far drivers side. On the other side of the plug/socket combination the wires are not the same colors as I mentioned above. The bundle is about 8 - 12 inches long. The lower end of the bundle - the end that I happened to discover, goes nowhere. It's just tucked up under the dash so it doesn't fall out, and the ends of all the wires are terminated with wire nuts and tape and secured together with a zip tie. Not factory.

What is this wiring for? Where is it supposed to go? Is it for an option that my Truck doesn't have? Any ideas?

Also, is a detailed factory type wiring diagram available somewhere on the forum? My Haynes shop manual is not nearly complete enough for real electrical system trouble shooting.

Thanks in advance for any help and a link to wiring diagrams.

 

Hey Dice,

It looks like it's been a while since your post. Hope you got your questions answered. I had the same thing and it turned out to be the guy who had the truck before me had an Intoxalock installed. It's one of those things you have to blow in to when you've had too many DUIs. The install/removal company just cuts wires and runs. At least yours were taped up.

Did you ever find a 2015 wiring diagram? I'm looking for one as well.

 

@nd4spdbh , you still holdin' the goods?

 

Hey Husky Dad. Thanks for the info about Intoxalock. Makes sense.

Check out https://www.tacomaworld.com/threads/2015-wiring.559639/ sent to me by TnShooter . Look down near the bottom.

and

http://www.autoshop101.com/forms/ToyEWB.pdf from Brianz1001

 

Hey dice,

Thanks for the info. That will definitely help.

 

Thanks for posting, that will be super helpful trouble shooting my 4x4 wiring

 

Can you post a picture? Sounds like either someone’s wiring for a trailer brake controller or part of a remote start system. But very hard to say just by the description