Coolant Temperature Sender
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| Illustration 1 | g00756898 |
(1) Coolant temperature sender (2) Engine lifting eye | |
The coolant temperature sender is mounted vertically in the cylinder head. The coolant temperature sender is located on the top left of the front of the cylinder head.
The coolant temperature sender sends an analog signal to the instrument panel. The final readout is in the form of an analog gauge.
Coolant Temperature Switch
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| Illustration 2 | g00756895 |
Location of the coolant temperature switch for the 3056 Marine engine (1) Coolant temperature switch (2) Engine lifting eye | |
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| Illustration 3 | g00790006 |
Location of the coolant temperature switch for the 3054 Marine engine (3) Coolant temperature switch (4) Domestic water heater | |
The coolant temperature switch is mounted horizontally in the water outlet manifold. The water outlet manifold is on the top front of the engine.
The coolant temperature switch monitors engine coolant temperature. A warning lamp on the instrument panel will be illuminated when the temperature is too high. An audible alarm will also sound when the temperature is too high.
Temperature Switch for the Timing Advance
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| Illustration 4 | g00756899 |
(1) Connection for the domestic water heater (2) Temperature switch for the timing advance (3) Jacket water pump | |
The temperature switch for the timing advance is mounted horizontally in the back of the water pump. The water pump is located on the front left of the engine.
The temperature switch for the timing advance is normally open. The signal determines if the fuel injection pump timing will be advanced or if the fuel injection pump timing will be retarded.
Oil Pressure Switch
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| Illustration 5 | g00756900 |
(1) Oil pressure switch | |
The oil pressure switch is located in the middle of the cylinder block on the left side.
The oil pressure switch performs two functions. The oil pressure switch will illuminate a warning lamp on the instrument panel when the oil pressure is too low. An audible alarm will also sound when the oil pressure is too low. The oil pressure switch also sends an analog signal to the oil pressure gauge on the instrument panel.
Failure of Sensors
All Sensors
A failure of any of the sensors may be caused by one of the following malfunctions:
- Sensor output is open.
- Sensor output is shorted to "- battery" or "+ battery".
- The sensor is out of specification.