I found the service manual files (on this forum I believe) and it contain entire folder of wiring diagrams for this truck (including wiring of optional accessories). However every diagram related to lights (marker, stop and blinkers) does not show any connections to trailer plug. Is this something not out of the box? Does anyone have a diagram how the wiring goes and where?

It can't be connected straight lamp circuits as T4R has blinkers separate from stop lights, but on the trailer hookup it is all US standard: stop and blinker on the trailer is the same bulb.

I'm wondering if it is easy to reconnect the trailer hookup to "Euro standard" where blinkers are separate from stop. I know I can use harness and get it connected to lamps, but if I can reuse existing trailer hookup it would be much easier.

Hi RysiuM,

Here's the diagram that you requested. I've circled the connecting socket in pink trace for convenience. I wasn't completely sure what your question(s) about this were so maybe you can clarify if there's anything further!

2011 4Runner "Trailer wiring circuit"


Cheers!

Out of curiosity what kind of trailer do you have?

As far as the wiring would it not be easier to adjust the wiring and lights on the trailer to US specifications? This doesn't limit your trailer to being towed by the 4Runner and vice versa.

To add one additional item to @rigtec 's post............

T4R comes pre-wired with a standard 4 wire and 7 wire blade (vehicle side) socket, socket is located under driver side rear bumper. Wiring diagram should be on covers. No need to add converters!



Attachment references common vehicle side & trailer side plugs. Was that what you were looking for?
Attachment 174939

Thanks a lot, that was it. This is the part I'm missing in the list of my diagrams. I like your source better - much more readable than mine. Where did you get it? (EDIT: Found it - it's Mitchell 1.)

So simply saying the towing socket turn signals (pin 1 and 7 on your diagram) come directly from flasher. So no magic here. I did not know that as "Trailer Tow Cuircuit" does not exist in my docs. I guess I need better manual.

Now answering other questions, I'm taking this car to Europe (yep, I love it so much I can't live without it ). So my questions are completely not related to US standards, but I'm trying to prepare what needs to be done to not get into trouble with EU police.

As for driving and towing in USA there is no brainer with this truck as like all you pointed out T4R 5th gen is already ready for towing stuff (I used 4-way connector for U Haul trailer and rented log splitter from Home depot. Worked like a charm.

For whoever would like to have these manuals in their library... Do it Yourself Automobile Repair Manuals - Mitchell 1 DIY

Mitchell's now has repair info for the 4 Runner for models thru 2014. I can't vouch for it, but have viewed their "sample" stuff and for the $$$ does not look too bad.

Then again, nashman69's 2010 FSM doesn't look to bad either.

Thanks rigtec...I had forgotten about the Mitchell's site.

Yes, that was it. But now I'm not sure if electrical diagrams from nashman89's 2010 FMS are relevant to 2012 SR5. In 2010 docs flasher is next to center console, but I think 2012 (and newer) have flasher as a part of Body ECU (I can't confirm that as I did not open the dash yet - still it's new to me). However from the Mitchell's diagram I may be able to separate trailer's stop light functionality from blinkers just by disconnecting blue wire from #16 in flasher unit (Stop Light Input), and use Brake Control pin on the trailer hookup for trailer's stop light.

On the similar note 5thGen DRL will not be "legal" in EU - they need to be separate UE certified lights. Based on 2010 FMS diagram I imagine it should be easy to mod just by disconnecting DRL wire going from Main Body ECU to the flasher unit and then connecting it to the new DRL relay (see diagram below). This change would work for adding LED type DRL, replacing front flasher bulbs with orange/white switchback LEDs or one of the DRL/Fog LED lights mod shown here on the forum.

How does this part of diagram looks on Mitchell's manuals?

Attached Images