Car Stereos: Reverse lights wire, rear view camera, rear view mirror

Question
QUESTION: Hello, I'm trying to wire my Kenwood KDC512 with a rear view camera so I have a couple quesitons.  What wire, and what is the best access point, to get the reverse wire on a 2002 Chevy Tahoe?

Thanks, Mike

ANSWER: Hi Mike,

My information shows the reverse wire as light green; it can be found in the wiring under the fuse box in the engine compartment.  However, you might try looking in the driver's side A-pillar.  Sometimes the rear view mirror in this truck has a built-in reverse indicator; if so, then the wire you need should be located in the wire bundle running up to the mirror.  Even if your mirror isn't equipped with the indicator, it's possible the wire is still there.

You should definitely test the wire before connecting to it.  To test for a reverse wire, use a multimeter set for DC volts.  Connect the black probe to a ground point (a metal brace under the dash, or the outside ring of the cigarette lighter, for example).  Set the parking brake and turn the key to the "run" position (don't start the engine).  Press the brake pedal, and shift to reverse.  Test the wire with the red probe.  The reverse wire should show 12 volts when you shift into reverse, and 0 volts in all other gears.

Hope this helps!

Brian

---------- FOLLOW-UP ----------

QUESTION: Great! Thanks Brian!  Also, is it imperitive that I hook up the 'parking' wire or can I leave that disconnected?  Lastly what do I connect the 'illumination'or dimmer (i forget what its called) wire to?
Thanks again for your help,
Mike

Answer
Mike,

The parking brake wire is a safety interlock; it's designed to ensure that you can't watch a movie on the DVD player while the vehicle is in motion.  The connection to the factory parking brake wire allows a picture to show on the screen when the brake is set.  The factory parking brake wire should be light blue; it can be found connected directly to the top of the parking brake mount.  If you leave this wire disconnected, you won't be able to see the picture when you play a DVD movie, iPod video, or an external video source.  (The rear view camera is meant to be used while driving, so it won't be affected).  Please don't ask how to bypass this function so that you can display movies while driving; that's a question I don't answer.

If you connect the illumination wire, the unit will dim the display when you turn your lights on.  It's meant to preserve your vision at night. There will be an illumination wire in the factory radio harness; usually it's dark brown.  If you used an adapter harness, there should be an orange wire in the harness that's meant for illumination.  If your truck is equipped with daytime running lights, it's possible that the illumination wire will be active whenever the ignition is on.  In this case, connecting the illumination wire will dim your display all the time.  Usually, though, you can adjust the display brightness manually in the head unit settings menu.

Hope this helps!

Brian