2006 SD Johnson 4 Stroke 9.9-15HP Outboards Service Manual, Page 69Get this manual
ELECTRICAL CAUTION SYSTEM
Oil Pressure Caution System Tests
IMPORTANT: Before checking the oil pressure
caution circuit, make sure the engine oil pressure is within specification
Oil Pressure Caution Lamp Circuit
Remove the blue lead wire from the oil pressure switch Start the engineTouch the blue lead wire to engine groundIf the caution lamp comes on, the oil pressure switch circuit and lamp are normal