16-70 ELECTRICAL SYSTEM
Switches and Sensors
Radiator Fan Switch Inspection
Remove the fan switch (see Cooling System chapter).
Suspend the switch [A] in a container of coolant so that
the temperature-sensing projection and threaded portion
Suspend an accurate thermometer [B] in the coolant.
The switch and thermometer must not touch the con-
tainer sides or bottom.
Place the container over a source of heat and gradu-
ally raise the temperature of the coolant while stirring the
Using the hand tester, measure the internal resistance
of the switch across the terminals at the temperatures
shown in the table.
If the hand tester does not show the specified values, re-
place the switch.
Fan Switch Resistance
From OFF to ON at 93 ∼ 103°C (199 ∼ 217°F)
Fan stops with the temperature 3 ∼ 8°C (38 ∼ 46°F)
lower than the operation temperature range.
ON: Less than 0.5 Ω
OFF: More than 10 MΩ