Crown Victoria V8-281 4.6L SFI (1998)
Temperature Gauge: Description and Operation
With Conventional Instrument Cluster
The engine coolant temperature indication system is a magnetic type system that consists of:
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Engine Coolant Temperature Gauge (located in instrument cluster).
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Engine coolant temperature sender (located in intake manifold).
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necessary circuitry.
Engine Coolant Temperature Gauge
The instrument cluster Engine Coolant Temperature Gauge has the following features:
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It consists of three primary coils of wire called the bobbin. One coil is wound at a 90 degree angle to the other two.
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When power is applied, current flowing through the bobbin and sending unit forms a magnetic field which varies in strength according to the
variable resistance of the engine coolant temperature sender.
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The bobbin/coil assembly is pressed into a metal housing which has two holes for dial mounting.
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A permanent magnet, to which a shaft and pointer are attached, rotates to align at this primary field, resulting in pointer position.
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The gauge pointer remains in position when the ignition switch is turned to OFF.
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The gauge pointer moves to the correct position whenever the ignition switch is turned to RUN.
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An instrument voltage regulator, as used on previous models, is not used.
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The Engine Coolant Temperature Gauge is located in the lower RH portion of the instrument cluster.
Engine Coolant Temperature (ECT) Sender
The engine coolant temperature sender is mounted into the engine intake manifold. The signal sent to Engine Coolant Temperature Gauge varies
with the resistance of engine coolant temperature sender. At cold coolant temperatures, the engine coolant temperature sender resistance is high,
and at high coolant temperatures the engine coolant temperature sender resistance is low.
