Mercury Optimax Models 135, 150, Direct Fuel Injection., Page 131Get this manual
WIRING DIAGRAMS
Outboard Multi-Function Gauge Setting
Model Test Display (All) Dip Switch Setting 4
Open 275 hp (3.4 Litre) Outboards (single engine) 4
Open 135-250 hp Outboards (single engine) 4
Open "Note" On Dual EngineSingle Fuel Tank Applications: Position Dip Switch "Open"4