Starting Circuit Junction Block

While trouble shooting a starting issue on my 93 Mondial T (It turned out to be worn solenoid contacts) I noticed what I consider an excessive voltage drop when cranking between the battery positive terminal and the stater positive lug. I am seeing about a 1.5 volt drop - excessive for the guage of the wire (35 mm^2) running between the positive terminal of the battery and the starter. The connection at the battery and starter is good and clean. But I noticed form the parts manual that the wire between the battery and the starter is not one continuous piece but two pieces. There is a terminal block connecting the two as well as the alternator positive output. Does anyone one know where this terminal block is located so I can check the connections there? Engine compartment