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.