Ok, here it goes.
The trailer brake jumper harness (I believe is toyota part number 82132-0c010, but don't hold me to that) Again should have come with your truck if you have the V6 with the factory towing package.
It has five wires coming from it. A black/red tracer, solid green, solid red, solid brown, and green/white tracer.
The connector plugs into the open connector which will be directly above the driver's side kick pannel. See Photo:
The BLACK W/ RED TRACER is your (+) power to the controller
The GREEN W/ WHITE TRACER is the stoplight switch. (where the truck tells the controller to engage the trailer brakes)
The SOLID RED is the output from the brake controller to the trailer itself
The SOLID BROWN is the ground (-)
The SOLID GREEN is the illumination circuit. (You will not need this for Drawtite and Reese controllers, just tape it up and ignore it.)
The Controller will have four openings and four screws in the back of it. Each opening will be marked as I have described above. You would then strip a quarter inch of insullation from the correct wire, insert it in the opening and tighten down the corresponding screw to clamp the wire down and make contact. Repeat for the remaining three wires. See picture.
That is the basics.
Now, in all honesty with the supplied length of wire from the harness, there is absolutely nowhere under the dash that you can mount the controller. So what I did was to go to the local hardware store, pick up 4 feet of each color wire. I think The RED W/ BLACK and the SOLID RED were 12 gauge, and the others were 16 gauge, but don't hold me to that. I soldered the new wire to the factory harness, heat shrunk the connections, taped the whole thing into it's own harness, and then routed it down through the kick pannel, under the door sill moulding, and out under the driver's seat following the wiring for the seat belt light. See Picture:
I velcroed the controller itself to the carpet under the seat, and then when I am towing, I plug the hand box in and leave it sitting in one of the cupholders in the console. See completed picture of truck and travel trailer at the campground from last weekend.
I have tried to make this as easy to follow as possible, and I hope that I have not offended anyone by over simplifying things. If anyone has any further questions feel free to ask, and I'll try to be of further assistance.
PS, Just for the rocord the activator III controller has been discontinued, not because it had any problems, but because it was fairly expensive compaired to it's competing models. IMHO, however it is the best controller for the money and the only practical one for our trucks.
Since I can't sleep I poked around on the net for prices, and this was the best I came up with.
though if you keep an eye out on e-bay you could do better, I got mine new on e-bay for about $59 plus shipping.