1976 MB 280S - Where is the fuel shut off valve?

I have recently developed a problem with one of my fuses being blown every now and then. It has been very spuratic and I haven't had the opportunity to trace it down yet. I think that it is #4 in the fuse box. It controls the some of the turn/tail lights, some of the gauges of the dash and of course the emergency fuel shut off valve. I am going to have to fuse this shut off valve separately while I trace down the problems. Any info as to where this valve is located?