I just completed this install, with the modification that instead of having the mirrors fold/unfold based on locking/unlocking the truck, I have them folding with the key in the OFF position, and unfolding with the key in ACC or better (ON or START). I did this by soldering in a small, simple 12v relay to the existing control box.

Thanks to daytonaviolet for the PDF writeup with pictures. It helped immensely. Honestly, I don't know how you'd get the motors installed without that PDF.

I do have a couple of things to add, based on my experience doing this:

1. My mirror connector was round instead of double-square, so I didn't have to separate the halves. (My 4R is a 2018 SR5 with no puddle lights or integrated turn signals, but it does have the heated mirrors.) The inner plug does have to be separated from the barrel though. In the second picture, you can see the tab that has to be pulled back to allow the plug to be pushed out (toward the wires). There's also a wedge on the other side of the barrel that has to be pryed.





2. Toyota included a hook-tab on the mirror base where it goes into the door, so that you can remove the 3 nuts holding the mirror to the door and not worry about the mirror falling out onto the ground. This is the kind of thing that I love about Toyota engineers.

3. I didn't tap any of the stock wires. Since I didn't use the lock/unlock signals, my only external connection was B+ always-on 12v power, which I got from an add-a-fuse into the "passenger power seat" fuse.

4. I routed the 2 motor wires through the stock wiring sleve, to protect them the same way the stock mirror wires are protected.

5. I routed the passenger-side control wires (red & black pair) from the driver's side kick panel, under the steering column, behind the HVAC control panel, down to the area right above the passenger knee airbag, then over to the passenger-side kick panel, and then into the door grommet from there. The included control wires were plenty long, with about a foot or 2 to spare.

I've also included a picture of the back of the painted cover piece, so you can see how to remove it. I think I pryed starting from the pointy part and working my way around the bottom.



Finished and tucked in: