Junction block X12 cavity 5 for dome light addition

[adam.busch]

I already know there are threads on the addition of footwell and step lights utilizing the grey wire, but I read in the attached picture from the manual that a pin can be added for the addition of dome light accessories. Does anyone know or have a picture labeled with the junction block where X12 would be located.

 

Also, since cavity 5 is not utilized, is it fused? If so where and how many amps? The second picture shows the plug and says the signal can be found there. Would that supply power or just be used on a relay to provided signal?

 

I know this method may sound more intensive than tapping a wire with a posi-tap, but it would leave wires alone and look factory. I'm just curious about going this route even though tapping the grey wire is easier.