there is just the mb style, two prong connector underneath the fuses. i had to open up the top part of the fuse box and lift up the fuses to find it. in the US cars the wires are green and brown. the only reason i could think of why it's in there is that the cluster cable might be part of a harness that winds up in the fusebox. you probably don't have to go to all that trouble, i don't see any reason why you can't leave the junction outside the fusebox.
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"