I have 0 gauge ran for 1:
with my battery in the trunk, as to keep my electronics all together
and my C/C has been removed.
My wire runs also follow on top of the factory ones.
The point is to keep this very clean and modular so it could all come out and would not have to be permanent to the car.
1) Replace headunit with Nexus
2) Add Power
3) Install Amp with Audio I/O
4) Run Remote Wire
The shroud for the headunit i cut back and made flush to mount on top of the nexus and using JBWeld to keep it from going anywhere. So now i really do have a nexus 7 headunit!
So now that we have a new headunit, next is power.
With a female car charger adapter from ebay tapping into the existing charger is easy
*A note on car chargers*
(The Nexus 7 needs 2amps to charge, check the output when selecting a USB charger)
The Nexus 7 charges normally even during heavy use and with the right power management can last a week on the battery.
With that tablet install stable, next is sound.
I cut a hole in the back and pulled the headphone jack out to allow for more play. Last thing you want to to snap it because of tight space.
The audio is a 3.5mm out via a 25ft (too long) Y-cable to a 4 channel amp, strictly for the internal speakers.
I also JBWelded the amp into the wheel well so I did not have to make a ton of holes in the body. (as this is a second hand temp amp, also amp isnt ment to be removed/modular)
Now to run the remote wire. With my C/C out I can re-purpose the standalone Cruise button for the amp. (Since it lights up too, thats a plus.)
Its as simple as a T splice!
What you end up with is a standalone tablet with a remote toggle, nothing crazy, and obviously you can install a switch anywhere for the remote instead of repurposing the C/C.
-- In reality you could stop here and run with touch screen controls... but i didnt. --
BEWARE-NOT FOR THE TIMID
*DISCLAIMER* SEE POST #30
1) Extend hardware buttons
2) Modify Horn
3) Volume buttons
4) Power button
(Get a friend that can actually solder for this or you will be buying a replacement ribbon cable, DONT MELT IT!)
The biggest PITA so far is extending the hardware controls from the Nexus ribbon cable.
(I went through 3 cables or so...)
Use the softest wire you can find and solder to the ribbon connections
The reason for this is so when you are bending wires around you dont break your soldering!
I used cat5 after getting the hardware buttons extended from the nexus to give me an easy connection.
There is a cat5 coupler JBWelded in the dash to connect the tablet connection to the car connection for easy removal.
Again I have no C/C so I have easy UP/DOWN buttons available right on my wheel. Tapping into those is the next step.
However before we can use the C/C buttons we need to modify the horn. (This is needed!)
The steering wheel and SRS reel need to come off and the SRS reel needs cracked open.
The horn and the C/C share a common ground, meaning your volume buttons will send the horn into a loop along with the volume if used.
To fix this the single wire for the horn needs moved over 1 notch to the empty slot. (You only have 1)
Original discovery post
Wiring diagram, for those that can read it: http://i.imgur.com/nRr49sQ.jpg
Then put the reel back together.
Since we disconnected from the common we need to run the new individual wire to the horn connector, using that empty slot we picked up.
Then disconnecting all the C/C wires from the connector (since we don't need those anyhow) and connecting the new standalone wire.
Gives us a completely separate line for the horn as we begin to keep the C/C wires, from the steering wheel, looped back inside for the tablet.
As for those other 2 wires, thats Vol Up/Down, again because of the shared ground.
and the green would be for the power button.
giving you something like this.
(Blue=Horn;Black=Wheel controls;Grey=Cat5 to tablet;Green=Power)
And finally the end result of tits.