Isolator installation is easy and rewarding. See dual battery Installation section first, if you plan on installing  a selector switch into the system.

Diagram #4  shows alternator w/ internal regulator and external sense will. This is the most typical system used on today's Inboard and Inboard/ Outboard boats.

Diagram #5 shows internal regulator with no sense wire from alternator. Note that here they show that the B1 output can be hooked to either Batt1 or Batt2.

Diagram #6 shows a Dual alternator internal regulator with sense wire hookup.