I know this is an older post but I thought I'd add my use case. I bought a used 2009 Yukon XL with DVD players installed into the headrests. Whoever did the install did use the MBEC connector but they wired the system directly to the "Run/Crank Feed" on Pin 7. It worked fine most of the time but every time I pulled up to a gas station and turned off the engine I would get the groan from the second row since it shuts off. I changed it to be this RAP-relay config. Much better. Now the DVD players ON state matches the radio.