Been having and put up with this for almost 2 years. I only use Sprinter only once per week normally. The battery is always drained unless I disconnect it. I have tried to trace the draw a few times. I think I found it. What happens is that whenI open the door the instrument cluster activates normally messing up my tests. I disabled the door switch this time. By monitoring a milliameter in series at the battery, I found that fuse 1 (15amp) in the fuse block on the side of the driver's seat is the problem. The fuse holder door says "power socket in driver's cabin". I'm thinking that this is the 12volt plug on the dash console. I disconnected the plug on the rear of this socket with no change. Looking in the service manual, this is indicated by fuse #3 instaed of #1 as the layout of the vehicle states. The manual states that fuse blocks may be different for some vehicles. How in the hell are we to figure which one to use? Also, since when placing the fuse back in causes the draw, I would think (dangerous word ) that there is a problem from the output of the fuse to the socket. Hope I'm not chasing my butt. I hope I'm on the right track and not fishing.