7 Pin Trailer Connector Wiring Diagram

I looked all over TW and Google trying to find out which colored wires performed which function.

I have a 2015 SR5 DC. I finally decided to dissect mine to find out. I was adding an extra 4 pin connector behind the back bumper, so I could plug in my aftermarket LED blinker/stop/tail light strip, and not have to unplug it when I plug in my 4 pin trailer harness.

This is what you'll need to know if you ever want to tap into the wires that feed the 7 pin connector. I drew this crude diagram to help explain.





I hope this helps some folks, because it's pretty tough finding this online. Don't try yellow to yellow and green to green because it ain't gonna work.

 

So yeah, this has been sorta hard to find in any Toyota documentation. The FSM electrical documentaiton is only circuit diagrams, not connector illustrations.

I just cross checked your work with other "standard 7-pin" connections on the web (and there are many variants), and was able to confirm that this is consistent with the following setup. Note that the pin assignments are consistent with yours, but not the wire colors.



And here is the complementary mirror image with the trailer side connection:





I'm looking because I currently have an issue I'm trying to sort out with my trailer battery apparently not charging while driving on our last trip, and I only know becaue my ARB fridge went into power save mode after 24 hours, which it has never done before. I suspect the trailer's charger/inverter has an issue, but I figures I better start all the way from the source. No fuses blow in the truck or the trailer, so now the fun begins...

 

And here are the etrailer diagrams. Ours is the middle "RV STANDARD." The pin assigments and wire colors are all consistent with the 2015 Tacoma plug you show above.

https://www.etrailer.com/faq-wiring.aspx

 

And now that it is daylight, I found this pretty helpful too. Jesus fuck.

 

thanks for the write up!

 

Trailer plug wiring is standardized across all vehicles, no point trying to find vehicle specific info.

 

How big is the fuse for the charging pin, 20amp?

 

12ga wire is rated to 20.

 

thank you

 

Damn this helps me out! Kind of ripped off my 7 pin plug and its lost somewhere in Uwharrie.. I have been trying to figure out which wire goes where for the new generic 7/4 pin combo plug.

 

I was just digging around for some info on a project I've got and this killed me lol. I may have had a similar situation. Thanks for the laugh!

 

For what it's worth: the blue is brake & right turn signal on the 2017--learned the hard way. Most of my electrical supplies were at work so I went off the diagram that came with the LEER harness for my LEER cap and tapped the designated line. Tested and worked only to notice next day that 3rd brake light now blinks with with right turn signal. Needless to say I brought my tester home and will confirm correct wire.

 

@Arkie-Marty not even sure if you're still on TW but THANK YOU THANK YOU THANK YOU!! I knocked my whole plug and wiring off about 2 years ago wheeling and this just saved me 225$ the dealership wanted for the pigtail. Worked perfectly. Easy to read. I'm towing once again baby!! Cheers to the extremely valuable info on this site!!

 

I’m fixing to wire up a leer camper and just to be clear... if I tie into one of the brake lights it’ll also flash with the turn signal?

 

Depends on the length.
12 AWg for 10 feet or less but you should go up to 10 for 15’ and 8 for 20’ to maintain voltage. Most guys cheat or don’t care or don’t know.

 

Is that 12V always hot? I hope so. I want to install bed lights and would rather not run a wire to the front.

 

No no no. This is for the trailer only. Do not tap into the 7 pin harness for any cap lights. For a cap 3rd brake light, you run the cap light hot lead to your truck's taillight housing and tap into the brake lamp hot wire.

 

What should I tap into for the camper interior light?

 

New member and new to a 16 Tacoma trd sport. When I bought the truck I didn’t realize it didn’t have the tow package. I’m looking to get oem 7 pin and 4 way flat to work. The thing is I have to go to the tail lights to make attachments. The question is if I cut the wires at the hitch side will it work with the diagrams shown. Ty in advance.

 

Do you know if the "brake controller output" pin has any output on our trucks if there's no brake controller installed? I wired up an extra third brake light to the brown pin, but of course it also blinks when I have the RH turn signal on.