Armrest USB Charging Mod

[Ontittech]

I've had a few people asking me about this. I had posted it else where when I did originally a few years ago, but they disappeared in a board crash, so I figured I would recreate it here to the best of my ability.

Here is the DIY on the USB install I did in my A4, as I was tired of cluttering up my center console and glove box with a million different DC Chargers for my stuff.

I apologize if things are a little out of order or I am missing something. I am going from Memory and my Photobucket to remind me

Things you will need:
-Small Flathead Screw Driver
-Standard Set of Sockets/wrenches
-Soldering iron and all the usual’s for soldering (Solder, Wire, Flux)
-DC Charger from a Cell Phone or other 5V charging device
-2 USB Ports (I got mine out of an old USB Hub and De-soldered them)
-A 4ft Length of At least 4 strand wire

Here is the finished product so you have an idea where we are headed.


First we need to remove the center console
Remove the Caps covering the Front console Bolts at the front of the dash where the dash meets the console on both the driver and passenger side


Then Remove the Bolt Under the Cup holders under the arm rest


Then the 2 Bolts under the ashtray at the rear of the console


Now the Console should be free, and after you engage the parking brake and remove the surround the console should just slide up and off the E-brake

(Sorry I don't have pics of this step)

Now we need to remove the Armrest from the rest of the console, there is a bolt underneath holding it on
(Again I don't know where the pic went of this step)

Next we need to give ourselves a little room to work

Looking at the armrest from underneath there is a screw that holds the two halves of the bottom of armrest together


Remove this screw and lightly pry the two halves of the bottom apart, by pushing the tabs on the left and right out, enough to get the wire through


Now we need to remove the Top of the arm rest from the rest of the armrest

Once the Console is removed then we can work on getting the Old RJ11 Phone Jack out.

Take the Lid off of the Arm rest and undo the two torx screws on the side to slide the wire and RJ11 jack out


Now we need to take the Cigarette adapter apart so we can start to solder in the wires

Under the Console are 2 screws that hold the Cigarette adapter onto the Console, you need to remove these screws


After removing the Cigarette Adapter from the Console, you need to get access to the electrical for it. There is a plastic cap covering the solder points, pop it off with a flat blade screwdriver



Now that everything is apart we can start making the modifications.

You will need to disassemble a DC Car charger. I used an old Blackberry charger, as I know it needs close to 5V with a tight tolerance, and it has an auto shut off when the battery is charged

What you need is the small circuit board inside of it


Unsolder the connections to the plug and the wires leading to the fuse

While we are at it, we might as well take apart the USB ports we will be using.
I used an old USB Hub I had lying around, and unsoldered the USB connectors from the board.

Now this was the hardest part of the whole process for me, threading the new wire back through the tiny space the stock wire went through. The reason I chose to change the wire fully was because I wanted something a little more robust than the stock 22Gauge 8 wire cable used for the RJ11

I found the easiest way was to feed the wire in through the top of the arm rest, and just keep pushing and wiggling until it appears.

Here is a pic of where the wire comes out into the armrest itself




Take your wire and add the DC Adapter circuit board in-line. Make sure you pay attention to the positive and negative on the board, as they aren't all the same
When you’re done it will look like this


Now solder the wire to the DC Adapter, again paying attention to the positive and negative connectors

Just be aware that you can't use much solder on the DC Adapter will catch as you try to open and close it, and the protective cover won't fit back on either
Speaking of the cover, once you've soldered on the wire, you can put it back on



Now take the end of the cable that you pulled through the arm rest and it is time to wire up the USB connectors. I had the luxury of having access to a CNC and some spare PVC Block that I could carve out a little holder for USB Connectors
The Power connectors for USB devices are Pin 1 and the Ground is Pin 4, 2-3 are used for data transfer
(as a Side note I am looking to possible use this to wire up as an iPod plug for my stereo this summer)

Here is how it will look when you are done soldering the USB connectors


After the USB plugs are wired in, you can feed the wire back through the top of the armrest, following where the old cable went


Once that is done you can reassemble everything back the opposite way it came apart. Be sure to test it before bolting things down for the final time, or you'll spend another hour pulling everything apart again to fix things.

Once it is all done, this is how it will look



I am sure they are probably steps I missed, but this should give you the gist of what needs to be done.

I'd say the entire project is probable a 2/10 for difficulty, as long as you have a little bit of electrical know how.

[beemercer]

Very nice work

[1redavant]

thats just creative. Very cool work.