Ford Explorer 2003 - N1 CHECK CIRCUIT 186 (BN;LB) FOR A SHORT TO VOLTAGE; N2 CHECK THE REAR WINDOW DEFROST RELAY; N4 CHECK CIRCUIT 1009 (OG;YE) FOR A SHORT TO GROUND; N5 CHECK CIRCUIT 688 (GY;LB) FOR A SHORT TO GROUND

PINPOINT TEST N: THE DEFROST SYSTEM WILL NOT SHUT OFF AUTOMATICALLY — ON AT ALL TIMES
Test Step Result / Action to Take
N1 CHECK CIRCUIT 186 (BN/LB) FOR A SHORT TO VOLTAGE
 Disconnect: Heated Backlight Relay.
 Ignition ON.
 Is the rear window defrost ON?
Yes
REPAIR the circuit. TEST the system for normal operation.
No
GO to N2.
N2 CHECK THE REAR WINDOW DEFROST RELAY
 Ignition OFF.
 Disconnect: Rear Window Defrost Relay.
 Carry out the rear window defrost relay component test.
Refer to Wiring Diagrams Cell 149 for component testing.
 Is the rear window defrost relay OK?
Yes
GO to N3.
No
INSTALL a new rear window defrost relay. TEST the system
for normal operation.
N3 CHECK THE REAR WINDOW DEFROST RELAY
 Ignition OFF.
 Measure the resistance between rear window defrost relay socket pin 86, circuit 1009 (OG/YE) harness
side and ground.
 Is the resistance greater than 10,000 ohms?
Yes
GO to N5.
No
GO to N4.
N4 CHECK CIRCUIT 1009 (OG/YE) FOR A SHORT TO GROUND
 Disconnect: ICM C220a.
 Measure the resistance between rear window defrost relay socket pin 86, circuit 1009 (OG/YE) harness
side and ground.
 Is the resistance greater than 10,000 ohms?
Yes
INSTALL a new ICM. REFER to Section 413-00. TEST the
system for normal operation.
No
REPAIR the circuit. TEST the system for normal operation.
N5 CHECK CIRCUIT 688 (GY/LB) FOR A SHORT TO GROUND
 Disconnect: Function Selector Switch C294b (Manual A/C Only) or DATC Module C228a..
 If equipped with manual A/C, measure the resistance between function selector switch C294b-12, circuit
688 (GY/LB) harness side and ground.
 If equipped with DATC, measure the resistance between DATC module C228a-12, circuit 688 (GY/LB)
harness side and ground.
 Is the resistance greater than 10,000 ohms?
Yes
If equipped with manual A/C, INSTALL a new manual climate
control assembly.
If equipped with DATC, INSTALL a new DATC climate control
assembly. REFER to Section 412-00.
No
REPAIR the circuit. TEST the system for normal operation.
17
2003 Explorer/Mountaineer Workshop Manual
1/17/2011
http://www.fordtechservice.dealerconnection.com/pubs/content/~WS3N/~MUS~LEN/19/S
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