1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 259Get this manual
2Remove screws and clampRemove screwsLift motor from end cap, taking care not to drop armature Motor and Electrical TestsRepair
Thermal Overload Switch Test
IMPORTANT: If trim pump has just been operated, do not run pump for approximately one minute before testing thermal overload switchAfter this period of time the switch should close (reset itself) and pump again may be operatedPerform the following check(s) only if switch does not reset itselfMOTOR ASSEMBLED Connect Ohmmeter (R scale) leads as shownIf switch is good, full continuity (zero ohms) will be indicatedIf full continuity is not indicated, disassemble motor and recheck switch per instructions, following