1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 260Get this manual
MOTOR DISASSEMBLED Connect Ohmmeter (R scale) leads as shownIf switch is good, full continuity (zero ohms) will be indicatedIf full continuity is not indicated, clean switch contact surfaces, using an ignition point file 3Connect 12-volt power supply to terminals and 4Solenoid should click and meter should read zero (0) ohms (full continuity)
cTest LeadsSwitch Contact Surface
4If meter does not read zero (0) ohms, replace solenoid
Motor Disassembly
1Remove screws and clamp