Right, been a bit quiet on this front for a while, but got it all in and working today, thanks to the help of my work friend who very kindly sacrificed his afternoon (and evening!) to sit outside in a cold car park soldering it all in for me (because I really suck at soldering!)

Anyway, not a lot to look at and no pics of the finished article because it got dark by the time we finished it, so I'll throw some up on tomorrow or Wednesday, but we started by soldering on the wires from the units plug to some wiring I bought in, and sheathed it up with a loom sleeve to make it look as OEM as possible;





I tried to match the colours as best as poss, although they ended up being hidden from the top end as we pulled the sleeve up and taped it up. But at least it made it easier at the bottom end for wire ID'ing.

So next we moved into the car, and started the bit I was dreading - cutting into the nice, virgin, loom for the stereo plug! Cut and spliced that with the wiring for the nav housing loom, and tried to make it as neat as poss with heat shrink and the original loom sleeving neatly cut and taped back in place. I really hate messy wiring, which is ironic as I'm totally crap at wiring, but there you go.



So with that done, we tapped into the positive (switched live) that goes to the dash cig socket, and spliced in the positive wire for a female 12v socket (the negative we just crimped a ring terminal to and grounded it on a chassis bolt, as there really wasn't much wiring down there to play with) and ran that behind the dash to provide power for the USB plug that powers the actual tablet. Then we repaired the broken off wires from the tablets PCB and extended the two wires that form the power switch for the tablet. Initially I wanted the tablet to automatically power on with ignition, and then power off with ignition cut, and after testing we found the power switch wiring has one wire thats a constant 3.7v live, and the other wire is nothing - so that when you press the power button, and hold for a few seconds, the circuit is completed and the tablet powers on. Press and hold again and it powers off. Just as we thought. However, we couldn't see an easy way to get it to complete the circuit, or feed it a few seconds worth of 3.7v on ignition on/off, in order to power it on/off. We looked at using the motor - when the unit opens the motors runs for about 2-3 seconds to open, and another 2-3 seconds to close, which should be enough time to supply power to turn it on and off, but testing the motor we found a) the motor was kicking out 9-10 volts and b) the red and black wire on it isn't actually positive and negative - it's forward and reverse! So the power side of it must be controlled at the PCB end of the housing. We decided it was too much grief to try stepping down the voltage from the motor to 3.7v for the power button, and also the power button works as a home button (like an iPhone) when you press and release quickly - so by wiring to the motor, using the tilt function would keep kicking you out the sat nav app back to the home screen.

So, in the end we decided to extend the wires from the power button down behind the dash to a teeny tiny press button, fitted out of site under the console - where I can easily reach it, but it can't be seen or knocked. Not ideal, as it means I manually have to turn it on and off, but at least all functionality is retained. No pics of that as it was dark by the time we got this all in.

So it's all in and working, functionality of the nav housing remains the same, and the functionality of the tablet itself remains the same - except the for the speaker which I left off, since I won't need it (I never use the spoken directions on sat navs).

Next steps are to try and hack TomTom Navigator to run on this, and then change the tablet itself to one with an AV input and plumb in a reverse camera.

Pics to follow when I can take some in daylight