ELECTRICAL
10.11
FAN MOTOR CURRENT DRAW
Connect ammeter leads
between exposed
Orange/Black terminals at
fan connection.
Connect only the Red/White
terminals at fan connection.
Ammeter
Acurrentdrawtestwillprovideagoodindicationoffan
motor condition. A worn or damaged fan motor will
draw morecurrent, which causesa reductioninblade
speed and reduced cooling.
1. Turn key to off.
2. Disconnect the thermistor.
3. Reconnect fan motor connector to place a DC
ammeter in series as shown in the Illustration.
4. Be sure fan blade is free to rotate.
5. T urn ignition key and engine stop switch to “ON”
position. Read thecurrent drawon ammeterwith
fan running.
6. If the fan motor draws more than 7.5 Amps,
replace the motor.
Fan Motor Current Draw:
Less Than 7.5 Amps
OIL COOLER FAN CONTROL
TEST
Oil Cooler Fan Notes
GThermistor resistance decreases with
temperature increase
GBoth fan and hot indicator should be on
with the thermistor unplugged
GFan blade should rotate drawing air in
through cooler (blowing on engine)
THERMISTOR RESISTANCE
VS. TEMPERATURE
Oil
Temperature
Resistance
± 20%
Fan
ON/OFF
Hot Light
ON/OFF
77° F
(25° C)
100KΩ Fan
OFF
OFF
240° F
(116° C)
3.5KΩ Fan
OFF
OFF
260° F
(127° C)
2.5KΩ Fan ON OFF
290° F
(143° C)
1.6KΩ Fan ON Hot Indi-
cator ON
Battery Voltage
Oil Cooler Fan Circuit
’HOT’ indication and fan ’ON’ with resistor
leads disconnected from module and key on
Power
Control
Module
Indicator
THERMISTOR
BLK/YEL
BLK/YEL
YEL/BLK
R/W
BLU/W
OR/BLK
YEL/BLK
RED/W
RED/W
BRN
Thermistor / Fan Control Test
GTurn key switch to ON and engine stop
switch to RUN. Do not start engine.
GTest voltage on R/W wire at vehicle control
module. R/W wire should have 12--14
Volts DC (battery voltage)
GDisconnect thermistor leads from the main
harness (Black/Yellow wires) - Fan and
Hot indicator ON? (If not, test
speedometer, fan motor and circuit)
GTest the resistance of the thermistor (refer
to temperature/resistance table).
Replace thermistor if out of specifiedrange.
See the wiring diagram or chart for
thermistor resistance values at various oil
temperatures. The resistance of the
thermistor is approximately100kΩ at 77°F.
GReplace vehicle control module and test
system if all else appears okay.
PartShark.com
877-999-5686
To Next Page
Loading...
Need help?
General
