1991 Johnson Evinrude EI 60 Loop V Models 150, 175 outboards Service Manual, Page 128Get this manual
Temperature Switch Test Purpose One heat sensitive switch is installed in each cylinder head to monitor engine temperatureBoth switches are connected in series with the control box warning hornIf either 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 positionTo ensure that the temperature sensing system can 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
rv ture switch from the cylinder headand remove the tempera1Disconnect the bullet connector(s)
2Using continuity light 01 hmmeter, make positive connections to the switchone lead to the switch lead and one lead to the metal portion of the switch 3Place the switch and an accurate industrial thermometer in warm automotive crankcase oil4Slowly increase the oil temperature using an external heat source&