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Disclaimer:I make no warranties about this information. You must verify all work that you do, I cannot. I also cannot guarantee that voltage spikes, dips, etc from your car won't cause damage. (but I'd certainly appreciate any comments on how to improve the design, perhaps with some diodes for over-voltage protection, and adding a 12V capacitor to smooth things out.This description is intended for those knowlegeable about soldering and using a mutlimeter. If you do not know how to do such things, then I'd suggest buying one of the available 3rd party pre-made adaptors instead.

Also, hey, this is no miracle of modern science, and maybe the info is already out there, I just hadn't seen it yet. Also its a cryin shame Apple makes the connector so hard to get as an OEM piece.

Easy power from an auto

My ultimate goal is described later on here, but in simpler terms, I want to use my 3rd gen iPod in the car, and I'm tired of it running out of juice (3g iPods have less battery power than gen 1/2). So I wanted to supply power to my iPod while in the car, and found that the 3rd party accessories available (so far) were way overkill (and thus overpriced) for my needs.

(I guess this connector should also work for connecting to a pack of batteries for airplane trips, etc), just make yourself 12V of batteries, and run that to a 6-pin male Firewire plug, and figure out how to explain that to airport security.. ok so maybe that idea has problems...)


I used this diagram of the Firewire pin-out as a reference, and verified all of my work using a voltmeter.


I made a Firewire<->Cigarette adaptor cable. A reasonable alternative is just to hard-wire to power in your car, removing the need for chopping up an adaptor.

  1. Solder a wire from pin 1 of the Firewire connector to the +12V output of the auto adaptor
  2. Solder a wire from pin 2 of the Firewire connector to the GND of the auto adaptor
  3. Use your voltmeter/multimeter to check for shorts, opens, etc.
  4. To be truly safe, use a lab bench power supply to power the cigarette connector and verify voltage output on Firewire pins.
  5. Plug this in to your car (without the iPod). Use multimeter to verify that pin of the Firewire adaptor is giving +12V with the ground probe of the multimeter on pin 2.
  6. Assuming your readings show you did this correctly, use the Apple Firewire<->Dock cable to connect to your Dock.
  7. Plug your iPod in to the Dock. Viola, you should now be supplying power so that you can use your iPod in the car indefinitely.
  8. Go back and tidy up any soldering, cover with electrical tape, etc.

This does not carry audio, but its step 1 for me. A full connector (3g iPod) is next. I expect it to involve buying a spare Apple Dock<->Firewire cable... opening the Dock side... resolding 3 of the 4 un-needed firewire wires to the Line-out Left/Right/Common (pins shown at iPoding.com.)

That should produce a perfect (for my purposes) 1 cable solution. On the Firewire side, I'll chop that off, hardwire the +12V/GND behind my dash, and connect the Line-out pins to a audio connector that can go to a 3rd AUX-in jack for my car stereo. (for a lot les cost, and a lot less bulk than what is so far available from 3rd-party iPod accessories vendors)


I am using the digital battery meter hack (numeric readout vs. 4-bar battery charge readout). When I left home tonite, I was at 426 (max for me is ~491). I drove maybe 40 minutes, playing the iPod the entire time. I was at 486 when I parked.


Moved to a separate page

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