I know some of you guys really have the wiring down in our cars. Does anyone know the pinout for 12v switched power available to the steering?

 

If you're looking from Ignition switched 12V inside the steering wheel, there is none. The lights and buttons are not Ignition fed.

Maybe if you can describe what you are trying to install we may be able to provide an alternative solution.

 

You are exactly the person I was thinking of when I made this post, you have some good info on wiring for our cars, do you have a manual you pull from? Anyways, I will be installing a steering wheel that needs power for LEDs and OBDII data passed to it, which would need to be 12V ignition switched, so that it is not always on, nor only on with parking lights. There should be some empty spots in the harness plug to run 12v if I have to, but I am not sure of what pins I would need for that specific plug, or where to even look to find them.

 

The idea sounds good, but off the top of my head there is no way it will work without disabling some of the functions of the steering wheel.
Here's why...all wires going to/from the steering wheel go through the Spiral Cable (aka Clock spring)...this is the limiting factor in what you are trying to do.
The Spiral Cable only has so many circuits that run through it...Airbag, Audio controls, Menu controls, Phone controls, heater...what did I miss?
If you haven't seen inside a Spiral cable, think of it as an oval track for slot cars...I assume everyone knows what slot cars are.
If there are 6 tracks, then the max number of cars is 6. You can less cars than tracks, but no less tracks than cars.

For example, if the Spiral Cable has a 6 pin connector going into it from the vehicle, and all 6 cavities have a wire, then the Spiral Cable has 6 tracks, and presumably 6 wires on the steering wheel connector, therefore another wire (car) cannot be added.
If the Spiral Cable has a 8 pin connector going into it from the vehicle, and only 6 cavities have a wire, then the Spiral Cable potentially has 8 tracks, and presumably 6 wires on the steering wheel connector, therefore adding 2 wires might be possible....might!
But if internally the spiral cable does not actually have a circuit for those 2 empty cavities on the connector, then it is not possible to add 2 more wires.

However, if you decided you don't need some, or all, of the steering wheel controls, you could repurpose those circuits for the new steering wheel.

At this point you would actually need to remove the Spiral cable and see how many wires (circuits) it has, if there are any unoccupied cavities in the connector, and do a continuity check to see if those unoccupied cavities actually have a complete circuit through the Spiral Cable.
That would be the first step, because if there are no empty cavities in the connector, then there's no point even going further.

I diagram would help to determine what circuits are there, but won't tell you which are not...if that makes sense.
If you had 6 wires, of an 8 pin connector, going in and out of the Spiral Cable, you wouldn't know if there were 2 empty circuits unless you physically checked it.
At that point if you're physically checking it, then the diagram isn't of much use...unless you plan to repurpose some circuits. Then you can determine which ones stay and which are going.

I think I made that sound complicated...lol!

 

Thanks, yes all that makes sense. Maybe I wrongfully assumed that the clockspring had traces that were unused, I guess there is only one way to find out now.

 

Once you open it up, and if you find no empty circuits, maybe there’s physical space to lay a second clock spring on top the existing one?

 

Unfortunately that's gonna be a no to both those ideas.
Opening it up could permanently damage it as the inner portion rotates with the steering wheel while the outer is fixed to the column...so if any of that gets damaged the unit is scrap.
There can only be one layer of traces in this case. In theory it's possible if the unit was built with more than one layer, but unfortunately it's not.

 

Ok...here is what I could find out for your project. I'm assuming you have a 2014-2016 IS...the 2017+ is different.
The connector going into the Spiral Cable from the vehicle harness is K26, it's a 14 pin connector. (Pins 7 and 14 appear to be empty - this is where you would look so see if there is a pin on Spiral Cable side connector)
The connectors coming out of the Spiral Cable on the steering wheel side are z4 and z5. (z4 - Pins 6 and 12 and z5 Pin 2 appear to be empty - this is where you would look so see if there is a pin on Spiral Cable side connector)
z4 is a 12 pin connector and z5 is a 4 pin connector.
The three connectors do not include the ones for the airbag as those are seperate and not to be touched.

 

Thanks, that is super helpful! I do have a 2015 but not have radar cruise or lane assist, so if those empty areas are unable to work, I wonder if I could utilize the distance control/lane departure control areas?

 

Yes...if you don't have Dynamic Cruise or LDA, then K26 pins 2 and 12 should be empty and hopefully have a circuit through the Spiral Cable. I can't foresee them making a different Spiral Cable just to eliminate two circuits.
Note that K26 pin 2 is actually spliced within the Spiral Cable to bring a circuit out on connector z4 and z5. It's the only circuit that does that in the Spiral Cable.

Potentially you should have at least 2 empty circuits, up to a maximum of 4 at this point.

Update us as you progress in determining how many circuits you have.

 

Here Z4 connector, it splits the wires out to the right and left side controls and both paddle shifters. Z5 (not pictured) is the connector for the cruise control.

 

That is not connector K26, hence the wire colors not aligning. K26 is a Black 14 pin connector...the one in the pic is a Black 12 pin connector.
On K26, pin cavities 7 and 14 are supposed to be empty, on the connector in the pic, pin 9 is empty.
To help determine pin location, if you look at your pic, there is a pink (or orange, I can't tell for sure) wire at the bottom right of the connector, that is pin 7, as noted by the little "7" molded in the square below it.

Here is the location of K26 (admit the spaghetti of connectors in the middle you will see a little blue arrow pointing to it...it's my best arrow, don't laugh!):


Below is what K26 looks like with the pin locations...this is the view from the front of the connector...the pin side.

 

Shoot, I re-edited the original before seeing your reply. Yes, I am not sure what connector this is, but it is the connector that plugs into the clock spring, and is split with the cruise control harness that also plugs into the clock spring. That wire that looks orange (pin 7) is actually pink.

I have left a pic showing where this connector is, and the white connector is for the cruise.

 

The connectors in that pic are z4 (Black one on the left) and z5 (white one on the right).
K26 is on the vehicle harness under to lower steering column cover, right below the spiral cable.

 

And the clock spring itself has 16 pins, I am not sure what I am looking for really.