I don't know if the PO screwed something up, but I'm sure this isn't the intended function.

Doesn't matter if I open a door or use the dimmer switch to try and turn on my dome, but the dome stays off and instead my rear cargo light comes on, wtf?

So where should I even begin to try and track down the f*** up?

And if I fix it so that my dome comes on instead, how then is the rear cargo lamp activated?

 

The cargo light should come on. Are you sure it's not just a bad bulb or blown fuse or something to the dome light keeping it from coming on?

 

Could be, I thought something was just mixed up lol. so the cargo light is supposed to come on with the door and dimmer switches, okay good to know, probably a blown bulb.