1995 Johnson/Evinrude Outboards 50 thru 70 3-cylinder Service Manual, Page 144Get this manual
Temperature Switch Test Purpose One heat sensitive switch is installed in the cylinder head to monitor engine temperatureThe switch is connected in series with the warning hornIf the switch senses temperature in excess of predetermined limit, contacts close and cause the warning horn to sound continuous tone when the key switch is in the ON position
fN=J To ensure that the temperature
sensing system can alert the operator during an overheating condition, it is very important that the warning horn be tested regularlySee Warning Horn, Section 1Testing
f41 1Disconnect the bullet connector(s) and remove the temperature switch from the cylinder head2Using continuity light or ohmmeter, make positive connections to the switchone lead to the switch lead and one lead to the metal portion of the switchf5l 3Place the switch and an accurate industrial thermometer in warm automotive crankcase oil4Slowly increase the oil temperature using an external heat source&