"Factory" 7pin Trailer Harness Installation

Can you post the diagram for that?

What is the wire for pin 2 in the IA4 connector? I think it's related to the TRD bed power outlet. Does it go from IA4 straight to the 100/400W dash switch?

 

It does. It also has a split to the switch, relay and inverter.

 

I may have a need for my brake controller soon, headed to Overland Expo West. Which will give me the incentive to finish installing it, mostly installing the rest of the power input leads/relays. I have a Bussmann box with extra room so instead of tearing open the factory fuse box I may use that.

 

@Sandman614 how do you pop out the socket of the IA4 connector that's held by the blue plastic bracket. The plug was cake but I've been fighting with the socket for almost an hour. I've got the wire plus terminal and fuse. I need my brake controller this weekend. Help!

Pic shows the socket next to IA4 (which I also need to remove) and shows the blue bracket or dock I was talking about

 

BUMPPP!!

 

Without tearing my truck apart I assume there's just a little tab you have to pinch holding it in there.

 

I thought you already added the wire to the back of IA4? Tab Yeah but it's not accessible without taking everything apart completely or downsizing like Matt Damon

 

This was 3 years ago, looking back at the OP I didn't reference IA4. If it's to add the rest of the power wires for the brake controller, I haven't done that yet.

 

I've just done it

 

Everything (almost) works and is completely factory (minus the reverse lights which I also - like @Sandman614 - rigged up with an old trailer harness. I did not buy the optional Toyota 4pin harness because it costs $100.
Instead I went to a junkyard and pulled all the wires, fuses, relays and the towing converter.
Battery charging does not work unless I pull the relay and jump the pins (but Toyota uses a wire so thin that all you get at the rear bumper is just a flicker.

In the same go I also added the bed power outlet (my truck,V6 SR5) was partially prewired for it so I got the rest from the junkyard too. Same issue, it only works when I pull the relay and jump the pins which effectively bypasses the dash switch (for which I was also prewired)

So the 12v+ leads to activate both those relays don't have juice. Even tho I wired it like it comes from the factory. Guess I'll splice those into the light green ignition wire in the engine fuse box. That should do the trick.

 

Welp, must have messed something up because ABS and parking brake lights are on solid, speedo and cruise don't work and neither does the AC/fan/heater...

Battery is good. All fuses are good and have power. What gives. Faaarrrrk

 

Ign 1 No2 fuse

 

Wish it was that easy but it's not.
Dome lights works...
Also test that fuse and even replaced it but no dice

I think my ABS actuator took a dump. Not that I need that stupid ABS but having a speedo is kinda nice lol

Edit: CEL is tripped too but I think that could be from having no speedo

 

What's the purple/white wire in the ID2 plug? The one in the top row middle between red reverse and yellow brake?