Ford Electric Ranger 2001 Manual page 342

412-03-10
DIAGNOSIS AND TESTING (Continued)
PINPOINT TEST F: A/C COMPRESSOR DOES NOT OPERATE (NO COOLING)
F1 CHECK A/C LOW PRESSURE SWITCH
• With key OFF, disconnect A/C low pressure switch C1973 and connect a Yes =
jumper wire between the P wire and PK/LB wire on A/C low pressure
switch C1973.
• With key ON, set the mode select knob to the A/C position, the
temperature control knob to full cool position, and the blower control
knob to HIGH speed position.
• Does the A/C compressor operate?
F2 CHECK A/C SYSTEM PRESSURE
• Connect R-134a Manifold Gauge Set to charge ports and observe the
A/C system pressure (with jumper wire still connected to A/C low
pressure switch C1973).
• Is the pressure above 345 kPa (50 psi)?
F3 CHECK A/C LOW PRESSURE SWITCH STATUS
• With key OFF, remove jumper wire and reconnect A/C low pressure
switch C1973.
• With key ON, set the mode select knob to the A/C position and monitor
the interface adapter assembly (IAA) module PID AC LOWP.
• Does the AC LOWP PID indicate DISABLE?
F4 CHECK A/C LOW PRESSURE SWITCH SIGNAL (12-VOLT
POWER) TO INTERFACE ADAPTER ASSEMBLY (IAA) MODULE
• Connect the 104-Pin Breakout Box (BOB) to the IAA module and IAA
module C1945.
• With key ON, set the mode select knob to the A/C position and measure
the voltage between BOB pin 56 and ground (BOB pin 80).
• Is the voltage greater than 10 volts?
F5 CHECK A/C SWITCHED POWER (12 VOLT) TO A/C LOW
PRESSURE SWITCH
• With key OFF, disconnect A/C low pressure switch C1973.
• With key ON, set the mode select knob to the A/C position and measure
the voltage between the P wire on A/C low pressure switch C1973 and
ground.
• Is the voltage greater than 10 volts?
F6 CHECK CIRCUIT 3232 (P) FOR OPEN
• With key OFF, measure the resistance of the P wire between A/C low
pressure switch C1973 and BOB pin 36.
• Is the resistance less than 5 ohms?
F7 CHECK A/C COMPRESSOR PWM OUTPUT SIGNAL FROM
INTERFACE ADAPTER ASSEMBLY (IAA) MODULE
• Connect the 104-Pin Breakout Box (BOB) to the IAA module and IAA
module C1945.
• With key ON, set the mode select knob to the A/C position, the
temperature control knob to the full cool position, and measure the
frequency between BOB pin 46 and ground (BOB pin 80).
• Is the frequency between 45 and 120 Hz?
F8 CHECK CIRCUIT 3026 (R/PK) FOR SHORT TO GROUND
(Continued)
Air Conditioning
TEST STEP ACTION TO TAKE
GO to F2.
GO to F3.
No =
Yes = REPLACE the A/C low
pressure switch.
No = CHECK refrigerant system
for leaks. REPAIR as
necessary. RECHARGE the
A/C system.
GO to F7.
Yes =
GO to F4.
No =
Yes = REPLACE the IAA module.
REFER to Section
No = GO to F5.
Yes = REPAIR the PK/LB wire
between A/C low pressure
switch C1973 and IAA
module C1945.
GO to F6.
No =
Yes = REPLACE the IAA module.
REFER to Section
No = REPAIR the P wire.
Yes = GO to F9.
No = GO to F8.
2001 Ranger EV, 01/2001
412-03-10
412-04.
412-04.