Mercury Mariner 200, 225 Optimax Outboards Service Manual, 90-855348, Page 119Get this manual
Warning System The outboard warning system incorporates warning light gauge (a) and warning horn (b)The warning horn is located inside the remote control or is part of the ignition key switch wiring harness
When the key switch is turned to the ON position, the warning lights and horn will turn on for moment as test to tell you the system is working
Warning System Signals
NOTE: The warning system Signals which includes audible and visual indicator involving the horn and lights will identify the potential problems listed in the chartProblem Horn Check Engine Light Yes Low Oil Light Yes Yes Over Heat Light Yes Water In Fuel Light Yes Engine Speed Reduction Activated (approx3000 RPM) No No