Ford 2001 Ranger, Manual

Page: 342 / 1218

412-03-10 412-03-10 Air Conditioning
DIAGNOSIS AND TESTING (Continued)
PINPOINT TEST F: A/C COMPRESSOR DOES NOT OPERATE (NO COOLING)
TEST STEP ACTION TO TAKE
F1 CHECK A/C LOW PRESSURE SWITCH
•
With key OFF, disconnect A/C low pressure switch C1973 and connect a Yes = GO to F2.
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 No = GO to F3.
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 Yes = REPLACE the A/C low
A/C system pressure (with jumper wire still connected to A/C low pressure switch.
pressure switch C1973).
•
Is the pressure above 345 kPa (50 psi)?
No = CHECK refrigerant system
for leaks. REPAIR as
necessary. RECHARGE the
A/C system.
F3 CHECK A/C LOW PRESSURE SWITCH STATUS
•
With key OFF, remove jumper wire and reconnect A/C low pressure Yes = GO to F7.
switch C1973.
•
With key ON, set the mode select knob to the A/C position and monitor No = GO to F4.
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 Yes = REPLACE the IAA module.
module C1945. REFER to Section 412-04 .
•
With key ON, set the mode select knob to the A/C position and measure No = GO to F5.
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. Yes = REPAIR the PK/LB wire
between A/C low pressure
switch C1973 and IAA
module C1945.
•
With key ON, set the mode select knob to the A/C position and measure No = GO to F6.
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 Yes = REPLACE the IAA module.
pressure switch C1973 and BOB pin 36. REFER to Section 412-04 .
•
Is the resistance less than 5 ohms?
No = REPAIR the P wire.
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 Yes = GO to F9.
module C1945.
•
With key ON, set the mode select knob to the A/C position, the No = GO to F8.
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)
2001 Ranger EV, 01/2001