2008 Infiniti M35 Auxiliary Inputs: Non-Nav Video "Hack"

As I previously discussed, I recently got a 2008 Infiniti M35 and am building a carputer to put in it. On the base model M35 (without navigation), there are auxiliary RCA inputs located behind the center armrest; however, when the car is moving or the parking brake is off, the auxiliary video input is disabled.

Since the carputer will use the auxiliary video input to display its content on the car's monitor, I needed to enable the auxiliary video input when the car is in motion. Although there are several great posts about enabling advanced navigation features while the M35 is moving, the "navigation hack" (registration required), doesn't apply to my non-nav/base M35.

Since I couldn't find any specific information about non-nav 2008 M35 models, and the wiring harnesses shown in the "navigation hack" are different, I had to do some research and testing to determine how to enable the auxiliary video inputs while the vehicle is moving. (On the positive side, I didn't need to add a switch in the glove box or cabin since my AV control unit doesn't use the vehicle speed sensor for navigation, which makes my mod more simple than the "navigation hack".) From the existing "navigation hack" descriptions, I knew I needed to look at two wires: the parking brake signal, and the vehicle speed sensor.

In order to access the AV control unit, I had to remove the cup holder, seat heater controls, shifter area, and the clock panel. For more detailed instructions on removing those items, with pictures, check the "navigation hack" thread. At first, I thought that simply cutting the parking brake signal wire and vehicle speed sensor would be sufficient; however, I eventually realized that they both actually had to be grounded. After cutting those two wires ~3" from the harness, I stripped 3/4″ off the ends still attached to the harness and used a wire nut to tie the two wires together with a piece of speaker wire, which I attached to a Torx bolt on the AV control unit’s metal frame.

Here's the wiring harnesses attached to the AV control unit, with the ones I modified marked in yellow, and the description of the parking brake signal and vehicle speed sensor wires (click to view the full-size images):

Disclaimer: This post is for educational purposes only. Although I have attempted to present accurate information, I can't guarantee the information is correct or applicable to your specific car. Modifying your M35 in this manner may void part or all of your warranty, cause damage to your car, cause unintended effects in your car's operation, cause injury to yourself or others, or be illegal in your jurisdiction.

15 thoughts on “2008 Infiniti M35 Auxiliary Inputs: Non-Nav Video "Hack"

  1. Dave

    I have a very similar story in that I also purchased a base model 2008 M35 (with 20K miles) just two weeks ago. On my first road trip, it occurred to me that I should start looking into hacking the video input so I could leverage it for other devices, like a Car PC, for Nav, etc. I'd like to keep up with your progress, as you are a couple of months ahead of me. Good luck!

  2. admin Post author

    @Dave: Thanks for the comment! The main issue I was concerned with was getting the video working while in motion, since it would be rather useless without that. Since I've solved that, my next step is to figure out where and how I'm going to mount the car PC.

  3. rick

    Thanks for posting this. I just picked up a 2008 base model too.

    Q: Did this leave your parking brake light on?

    Thanks

  4. admin Post author

    @rick: Nope. I suspect there are multiple wires from the actual parking brake (or parking brake sensor), one of which would go to the parking brake light on the dash, while another is the wire going to the AV control unit that I've grounded.

  5. Dave

    I've been researching a number of video-out options, and testing a few with an old laptop plugged into the composite video in on the M35. I've tried S-Video to Composite cables as well as an VGA to composite converter. The vga converter was slightly better since I could adjust HV sync to fill the screen better. At 800×600 or 1024×768 the desktop is too fuzzy to really use. I'm wondering if a real CarPC user interface (rather than a windows desktop) will make a big difference.

    How has your success been with using the composite video for the screen? have you found it usable? I've read every ripplinghurst post on the internet as he tried to hack into the M35 screen unsuccessfully…so I'm wondering if composite is really that bad (with the right user interface) and I'm chasing something (vga) that's not really worth it.

  6. Dave

    I've tried out "ride runner" with the composite inputs and it's not too bad. I'll probably go with the touch screen overlay…and try out the composite inputs for the stock monitor.

  7. admin Post author

    @Dave Sounds good. I think the key to using the composite inputs will be to make sure your video card supports the proper resolution. Since I'm guessing the composite inputs primarily exist to display output from a portable DVD player, whatever resolution those usually use would probably be the best way to go.. 856×480 maybe?

  8. Dave

    What I did get is a PC to TV converter box, takes vga input and converts it to composite. the nice thing about the box is that it's USB powered, easy sync adjustments to get the image to fill the monitor exactly (rather that needing to do those on the laptop), color and contrast displays. I played with different res and, yes, getting just the right resolution will probably help. ride runner seemed to work best out of the box with 800×600 and that in turn looked pretty decent on the composite display.

    have you made any progress with the overlay?

  9. admin Post author

    @Dave Unfortunately, I haven't had much time to work on this recently. I have tested the overlay and it works, but I haven't mounted the touchscreen in the car yet since I think that will take significant work (disassembling most of the dash, I suspect?). Alternatively, I've wondered if I could simply pry the bottom of the plastic around the LCD out enough to shove the touchscreen wire down, since then I would just need to disassemble the gear shift and AV area again to get it to the PC. Either way, I need to find a way to find or fabricate a piece of plastic to go around the touchscreen overlay so if you have any thoughts on that, that would helpful.

    Also, I'm left wondering where to mount the PC. I would think the trunk is the best place, and I've thought of trying to use the power from the XM satellite device. Otherwise I'll probably just take it to a car audio shop and have them run the power from the battery to the trunk, like they would for an amp. Of course, putting it in the trunk means getting the touchscreen overlay USB cable all the way to the trunk.. or some kind of wireless USB extender?

    2)

  10. Tim

    Followed your instructions and they worked perfectly! thanks for sharing the knowledge! I was thinking about hooking up a WD media player to this and wondering where the best place to be to mount this would be. Thanks for the help!

  11. admin Post author

    @Tim I still haven't mounted my carputer yet, as I've had the same dilemma of where to put it. A WD media player does seem like a good idea though, as it would be very easy to hook up, cheap, and more simple than adding a touchscreen overlay, running power for a carputer, etc. The downside, of course, is you wouldn't get GPS, Internet connectivity, camera[s], etc. Depending on how much heat it emits, I would probably just put it inside the armrest area. Have you tried plugging it in yet and checking the resolution out? Does it look good? I've often considered getting something similar (maybe an iPod/Zune with video-out?) as a stop-gap measure until I have time to mount and wire everything else.

  12. marvin

    I need a device I can connect to my factory radio and be able to watch movies through a dvd. I have a 2006 M35 without navigation.

  13. admin Post author

    @TMize I'm not sure how your Journey model would differ from my base model, unfortunately. The only thing I can suggest is to find a manual with pictures that match your A/V unit.

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