Ford 2001 Ranger, Manual

Page: 230 / 1218

303-03-9 303-03-9 Engine Cooling
DIAGNOSIS AND TESTING (Continued)
PINPOINT TEST D: COOLING FAN DOES NOT OPERATE
TEST STEP ACTION TO TAKE
•
With key OFF, measure the resistance between the BK wire on the Yes = GO to D11.
cooling fan C1967 and ground.
•
Is the resistance less than 5 ohms?
No = REPAIR the BK wire.
D11 CHECK FAN HIGH SPEED RELAY CONTROL CIRCUIT
•
With key OFF, remove the fan high speed relay from the cooling fan Yes = GO to D13.
relay box.
•
Enter the IAA module active command mode FAN SPEED CONTROL, No = GO to D12.
set the active command FAN SPD to HIGH, and measure the resistance
between pin 1 on the fan high speed relay C1955 and ground.
•
Is the resistance less than 5 ohms?
D12 CHECK CIRCUIT 3829 (LB/BK) FOR OPEN
•
Connect 104-Pin Breakout Box (BOB) to interface adapter assembly Yes = REPLACE the IAA module.
(IAA) module C1945; leave IAA module disconnected. REFER to Section 412-04.
•
With key OFF, measure the resistance of the LB/BK wire between pin 1 No = REPAIR the LB/BK wire.
on the fan high speed relay C1955 and BOB pin 101.
•
Is the resistance less than 5 ohms?
D13 CHECK CIRCUIT 261 (O/BK) FOR OPEN
•
With key OFF, measure the resistance of the O/BK wire between cooling Yes = REPLACE the fan high
fan C1967 and pin 5 on the fan high speed relay C1955. speed relay.
•
Is the resistance less than 5 ohms?
No = REPAIR the O/BK wire.
PINPOINT TEST E: COOLING FAN RUNS AT LOW SPEED AT ALL TIMES
TEST STEP ACTION TO TAKE
E1 CHECK CIRCUIT 260 (R/O) FOR SHORT TO POWER
•
Remove the fan low speed relay from the cooling fan relay box. Yes = GO to E2.
•
Does the cooling fan stop running?
No = REPAIR the R/O wire.
E2 CHECK FAN LOW SPEED RELAY
•
Measure the resistance between terminals 30 and 87 on the fan low Yes = REPLACE the fan low
speed relay. speed relay.
•
Is the resistance less than 5 ohms?
No = GO to E3.
E3 CHECK CIRCUIT 3828 (O/BK) FOR SHORT TO GROUND
•
With key OFF, disconnect interface adapter assembly (IAA) module Yes = REPLACE the IAA module.
C1945 and measure the resistance between pin 86 on the fan low speed REFER to Section 412-04.
relay C1954 and ground.
•
Is the resistance greater than 10,000 ohms?
No = REPAIR the O/BK wire.
PINPOINT TEST F: COOLING FAN RUNS AT HIGH SPEED AT ALL TIMES
TEST STEP ACTION TO TAKE
F1 CHECK CIRCUIT 261 (O/BK) FOR SHORT TO POWER
•
Remove the fan high speed relay from the cooling fan relay box. Yes = GO to F2.
•
Does the cooling fan stop running?
No = REPAIR the O/BK wire.
F2 CHECK FAN HIGH SPEED RELAY
•
Measure the resistance between terminals 3 and 5 on the fan high speed Yes = REPLACE the fan high
relay. speed relay.
•
Is the resistance less than 5 ohms?
No = GO to F3.
F3 CHECK CIRCUIT 3829 (LB/BK) FOR SHORT TO GROUND
•
With key OFF, disconnect interface adapter assembly (IAA) module Yes = REPLACE the IAA module.
C1945 and measure the resistance between pin 1 on the fan high speed REFER to Section 412-04.
relay C1955 and ground.
•
Is the resistance greater than 10,000 ohms?
No = REPAIR the LB/BK wire.
2001 Ranger EV, 01/2001