Ford 2001 Ranger, Manual

Page: 229 / 1218

303-03-8 303-03-8 Engine Cooling
DIAGNOSIS AND TESTING (Continued)
PINPOINT TEST D: COOLING FAN DOES NOT OPERATE
TEST STEP ACTION TO TAKE
•
With key OFF, remove the fan low speed relay from the cooling fan No = REPAIR as necessary.
relay box and measure the voltage between pins 85, 87 on the fan low
speed relay C1954 and ground. (V > 10 volts)
•
With key OFF, remove the fan high speed relay from the cooling fan
relay box and measure the voltage between pins 2, 3 on the fan high
speed relay C1955 and ground. (V > 10 volts)
•
Is everything OK?
D2 CHECK LOW SPEED FAN OPERATION
•
Enter the interface adapter assembly (IAA) module active command Yes = GO to D8.
mode FAN SPEED CONTROL and set the active command FAN SPD
to LOW.
•
Does the cooling fan operate at low speed?
No = GO to D3.
D3 CHECK POWER TO COOLING FAN
•
With key OFF, disconnect cooling fan C1967. Yes = REPLACE the cooling fan.
•
Enter the IAA module active command mode FAN SPEED CONTROL, No = GO to D4.
set the active command FAN SPD to LOW, and measure the voltage
between the R/O wire and BK wire on cooling fan C1967.
•
Is the voltage greater than 10 volts?
D4 CHECK GROUND TO COOLING FAN
•
With key OFF, measure the resistance between the BK wire on the Yes = GO to D5.
cooling fan C1967 and ground.
•
Is the resistance less than 5 ohms?
No = REPAIR the BK wire.
D5 CHECK FAN LOW SPEED RELAY CONTROL CIRCUIT
•
With key OFF, remove the fan low speed relay from the cooling fan Yes = GO to D7.
relay box.
•
Enter the IAA module active command mode FAN SPEED CONTROL, No = GO to D6.
set the active command FAN SPD to LOW, and measure the resistance
between pin 86 on the fan low speed relay C1954 and ground.
•
Is the resistance less than 5 ohms?
D6 CHECK CIRCUIT 3828 (O/BK) FOR OPEN
•
Connect 104-Pin Breakout Box (BOB) to IAA module C1945; leave IAA Yes = REPLACE the IAA module.
module disconnected. REFER to Section 412-04.
•
With key OFF, measure the resistance of the O/BK wire between pin 86 No = REPAIR the O/BK wire.
on the fan low speed relay C1954 and BOB pin 69.
•
Is the resistance less than 5 ohms?
D7 CHECK CIRCUIT 260 (R/O) FOR OPEN
•
With key OFF, measure the resistance of the R/O wire between cooling Yes = REPLACE the fan low
fan C1967 and pin 30 on the fan low speed relay C1954. speed relay.
•
Is the resistance less than 5 ohms?
No = REPAIR the R/O wire.
D8 CHECK HIGH SPEED FAN OPERATION
•
Enter the IAA module active command mode FAN SPEED CONTROL Yes = System OK. CHECK wiring
and set the active command FAN SPD to HIGH. for intermittent connections.
•
Does the cooling fan operate at high speed?
No = GO to D9.
D9 CHECK POWER TO COOLING FAN
•
With key OFF, disconnect cooling fan C1967. Yes = REPLACE the cooling fan.
•
Enter the IAA module active command mode FAN SPEED CONTROL, No = GO to D10.
set the active command FAN SPD to HIGH, and measure the voltage
between the O/BK wire and BK wire on cooling fan C1967.
•
Is the voltage greater than 10 volts?
D10 CHECK GROUND TO COOLING FAN
(Continued)
2001 Ranger EV, 01/2001