mercedes/sl-class/2003-2012

1999 mercedes benz sl500 battery positive terminal wires

I just finished work on my transmission and was going to do a flush. I hooked up the battery to start it and when my son turned the key sparks flew from the starter area. I went back to check the battery and I forgot to connect a small black cable to the + positive terminal (it was tucked behind the panel) now the car dash lights up everything works except the starter wont even click (1) what was that wire I didn't connect and (2) did I fry the starter (3) is there a fuse or relay to replace and where is it (I checked everywhere)any help would be greatly appreciated.

 

Thank You

51