So, for a while, I’ve been testing out some Dashboard Cameras and iPhone chargers that utilize the Cigarette Lighter Socket in the car. When I decided to mount the equipment to the car permanently, I wanted to draw power from the car from somewhere other than the Cigarette Lighter Socket where I had to keep the ash tray open. I also wanted the power to turn on and shut off with the ignition of the vehicle.
On the Cayenne’s two fuse box by the driver’s side and passenger sideÂ doors, there are some open sockets for factory installed options. In the vehicle manual, it should be marked “auxiliary” or “un-used”. But if you peek into the sockets, you’ll see that one side of the fuse socket will have a metal conductor. Using a voltmeter, check that you get 12V when you turn on the ignition and goesÂ to zero when you shut off the car. If you still have something like 0.3V when you shut off the ignition, that fuse is on a timed relay from the CAN-BUS system and not a TRUE switched 12V socket. Don’t trust my photos.Â Each vehicle is wired differently due to the factory options available on the Cayenne. Always check and re-check with a voltmeter.
There are two of these switched 12V fuse sockets in both fuse boxes for a total of four (4). You may use a fuse tap, a blade socket, or add-a-fuse type piggy-back to get the 12V+ from these socket. On the driver’s side fuse box, there is a hex head screw on the metal frame of the dash to supply the Ground (GND) but this is absent on the passenger side… unless you’re vehicle has been pre-configured with a grounding post for optional equipment. For those who are not so lucky, you can easily tap a hole into the metal frame to screw in a grounding post.