Ford 2001 Ranger, Manual

Page: 308 / 1218

412-02-14 412-02-14 Heating and Ventilation
DIAGNOSIS AND TESTING (Continued)
PINPOINT TEST E: DTC C1776 HEATER SYSTEM FAILURE
TEST STEP ACTION TO TAKE
•
Is the resistance greater than 10,000 ohms?
No = REPLACE the HVPDB.
REFER to Section 414-03A
or Section 414-03B .
E16 CHECK SYSTEM
•
With key OFF, reconnect all component connectors that were Yes = REPLACE the PTC
disconnected. switching module.
REPLACE the 25A PTC
HTR fuse. REFER to
Section 414-03A or
Section 414-03B .
•
With key ON, set the mode select knob to the PANEL/FLOOR position, No = System OK.
the temperature control knob to the full warm position, and the blower
control knob to the HIGH speed position.
•
Does the 25A PTC HTR high-voltage fuse fail again?
E17 INSPECT PTC HEATER CORES
•
Remove the PTC heater core and check for contaminants (excessive Yes = REPLACE the PTC
moisture or debris) on the heater core. switching module.
•
Is the heater core clear of contaminants?
No = REMOVE the contaminants.
If necessary, REPLACE the
PTC heater core.
PINPOINT TEST F: DTC C1779 BLOWER SWITCH FAILURE
TEST STEP ACTION TO TAKE
F1 CHECK BLOWER SWITCH STATUS
•
With key ON, monitor the interface adapter assembly (IAA) module PID Yes = System OK. CHECK wiring
BLOWER while rotating the blower control knob through all the blower for intermittent connections.
speed positions.
•
Does the BLOWER PID agree with all the blower speed positions?
No = GO to F2.
F2 CHECK BLOWER SWITCH INPUT VOLTAGE REFERENCES
•
Connect 104-Pin Breakout Box (BOB) to IAA module and IAA module Yes = GO to F7.
C1945.
•
With key ON, measure the voltage between BOB pins 60, 61, 62 and No = GO to F3.
ground (BOB pin 80).
•
Do the voltages fluctuate between 0 and 2.8 volts?
F3 CHECK GROUND TO BLOWER SWITCH
•
With key OFF, disconnect blower switch C232 and measure the Yes = GO to F4.
resistance between the BK wire on blower switch C232 and ground.
•
Is the resistance less than 5 ohms?
No = REPAIR the BK wire.
F4 CHECK CIRCUITS 751 (DB/W), 752 (Y/R), AND 754 (LG/W) FOR
OPEN(S)
•
With key OFF, disconnect IAA module from BOB; leave BOB Yes = GO to F5.
connected to IAA module C1945.
•
With key OFF, measure the resistance of the DB/W wire between blower No = REPAIR the wire(s) in
switch C232 and BOB pin 62. question.
•
With key OFF, measure the resistance of the Y/R wire between blower
switch C232 and BOB pin 61.
•
With key OFF, measure the resistance of the LG/W wire between blower
switch C232 and BOB pin 60.
•
Are the resistances less than 5 ohms?
F5 CHECK CIRCUITS 751 (DB/W), 752 (Y/R), AND 754 (LG/W) FOR
SHORT(S) TO GROUND
(Continued)
2001 Ranger EV, 01/2001