I found the orange wire in the trailer brake bundle, but according to the GM Upfitters site, that is for the above cab brake light. I tested it, and of course it worked when in reverse...because my foot was on the brake! Ha,ha. Anyway, I've attached a PDF that I found that has some new info.
IanF - Do you think I testing the same Orange wire you were referring to?
Also another question for the masses: If I use pin 8 in block X10, will I need to use a step-down in the line so I don't fry the monitor? I'm thinking that wire will be 12V and my accessory plug has 12/24V DC 0.3A stamped on it.
Here is the text from what I found:
"Here is where I tapped into for my backup camera. It is called the MBEC box. You can use the "Reverse" connection (pin 8 in block X10) for the backup signal. Then you can use the ignition or accessory (pins 7 and 8 in block X14) for the power on the camera itself. The MBEC box is located under the drivers side of the dash on the firewall, just above where your left foot would rest to the right of the parking brake. It has a black cover on it that you simply pull off. If you click on the graphic, it will zoom in so you can see it better."