1988 Johnson Evinrude CC 60 thru 75 outboards Service Manual, Page 159Get this manual
Temperature Switch Test Purpose One heat sensitive switch is installed in the cylinder head to monitor engine temperature The switch is connected in series with the control box warning horn If 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 INotel To ensure that th.e temperature .ca.n alert the operator dUring an overheating condition, It IS very important that the control box warning horn be tested on regular basisSee Warning Horn Test, Section 1Testing
L!J ture switch from the cylinder head
1Disconnect the bullet connector(s) and remove the tempera-
2Using continuity light or ohmmeter, make positive connections to the switchone lead to the switch lead and one lead to the metal portion of the switchf513 Place the switch and an accurate industrial thermometer in warm automotive crankcase oil4 Slowly increase the oil temperature using an external heat source5Slowly increase the oil temperature using an external heat sourceTo avoid possible fire or explosion: Use suitable container for the oil Use an oil that has flash point above 300 (150 C), such as OMC Cobra 4-Cycle Motor Oil Do not use open flame as heat source5The switch must react to the changing temperature as follows: Wire Color Tan White Black Switch Closed Switch Open