I got a weird one that's happened twice now. The cargo lights don't come on when I open the rear doors, but they do when I open the side sliding door. They never have come on when I opened the rear doors, so I never thought much about it, but since they come on in other Sprinters, it's probably something I should have taken care of.
But, twice now, last week and a couple of days ago, I'll be driving along and suddenly all of the cargo lights will come on. First time it happened I was out on the Interstate and really couldn't just pull over for that, so I drove on and was gonna pull off at the next exit. 5 minutes later they just went out. Second time it happened I was able to pull over, and I opened doors and closed doors, played with the contacts and everything, nothing. So I drove on to see if they'd go out. A few minutes later they went out. Weird.
I change my both the transmission and rear end at 60,000 miles. Doing the rear end at the same time as the transmission is easy, quick and cheap.