Just a quick note to prevent others from having the same problem I had.
2 weeks ago I was on a trip with my family to upstate NY in our 2013 EXT (on a 2013 chassis). We checked in to a hotel for the night and it was around 0F when we woke up. I went outside to warm the rig up for the family, and was met with just the *click* from the ignition and nothing else. I'll spare you the troubleshooting that we did, but eventually we got on the horn with MB to do some last ditch ideas.
MB had me check the starter fuse, which they indicated was in slot 23 in the fuse box. I verified the fuse location in the owners manual, and it matched. So I crawled under the dash, looked at fuse 23, and it was fine. That was the last straw, so my AS got towed to the closest Sprinter dealer (100 miles away) and my family continued on in a rental for the rest of our trip.
As it turns out, the starter fuse WAS blown... it just wasn't fuse 23. MB had changed the fuse location to 28 in the 2013 Sprinters and not updated the manual. The dealer swapped in a new fuse and the AS fired right up.
Anyhoo, a weekend of aggravation, a return trip to retrieve the rig, and a very expensive tow/rental reimbursement for MB, all b/c of a mislabeled fuse. So, make a mental note that the starter fuse isn't where you think it is. I hope no one else has this problem