1996 Johnson/Evinrude Outboards 8 thru 15 Four-Stroke Service Manual, Page 121Get this manual
Temperature Switch Test9.915 Models Purpose heat sensitive switch is installed in the cylinder head to monitor engine temperatureThe switch is connected in series with the warning systemIf the switch senses temperature in excess of predetermined limit, contacts close and cause the System Check gauge "WATER TEMP" light to turn on and the warning horn to sound for ten secondsIf boat is not equipped with System Check gauge, the warning horn will sound continuous tone
INote To ensure that the temperature sensing system
can alert the operator during an overheating condition, test the warning system as described in Section 8, System Check Engine MonitorW
Testing 1Disconnect the connector and remove the temperature switch from the cylinder head