Ford Electric Ranger 2001 Manual page 230

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