Tow haul switch missing 2008 sr5 dcab, can I buy one? trying to upgrade a base model, advise is welc

as I am learning and taking apart this truck, I found a lot of functions missing and I am trying to upgrade as much as I can. Since the harnesses are common in most trims, I wonder if just buying the switches will work.
1. the Tow Haul is missing, I wonder if I buy the button will it work?
2. how do you find a comprehensible wiring to tap wire in the cab (next to the parking break).
3. trying to identify "dead ends"
4. I am trying to add a 15 amp circuit and I would like to tap on to the connectors that are against the wall by the parking break so it will be switch controlled, any advice?
5. How to connect an OBD to a radio? which harness would that be?

Also on the right hand of the steering wheel there is another floating connector, what is that one for? see pic below.

 

Is it a column shift or console shift?

 

Console. But it does not have anything that would allude to the truck has a towing package with in the cab, I read and watch the Toyota instructions and for the model I have the directions is to drive on "s", I just would like the button just for a peace of mind.

 

Go to Toyota.com>Owners>Specifications and input your VIN to determine if your truck has the tow package. If your truck doesn't have the tow package, then retrofitting a tow/haul button will be more complicated than simply mounting a button in the dash and plugging into an existing harness (assumes the proper harness already exists).

I suspect the tow/haul button may have begun with the 5.7L. Tow/Haul affects transmission shift points, and I believe engine timing. If those functions aren't already programmed into the ECM, and the right harness connectors aren't available, I don't know how it can be done without a LOT of trouble and expense. If it was possible to do it with the resources available to the average owner, I think I would have already seen a mod thread on this or other Tundra forums.

 

gotcha. just making sure you werent assuming there was a button on the dash just to realize it is at the end of the stalk.

unfortunately, i think adding this button is going to be way way more involved than just adding the button. even something well documented and easy like adding the info button for mpg, etc requries some people to add certain wires, other people to add other wires. maybe im wrong, but i wouldnt count on it.

tow haul mode will quicken downshifts when braking, and delay upshifts when accelerating. i think your best bet is going to be using the s mode. idk if tow haul mode in our trucks also eliminates the OD gear to lessen the jumping between gears at highways speeds as well, but s mode will also do that for you.