Pinpoint Test M: The Defrost System Is Inoperative
Normal Operation
Under normal operation, the heated backlight relay receives power from the central junction box through circuit 185 (BK). When the rear window defrost switch is depressed on the climate
control assembly, a ground signal is sent to the instrument cluster module (ICM) through the circuit 688 (GY/LB). When the ICM receives ground through circuit 688 (GY/LB), the ICM
grounds circuit 1009 (OG/YE) to activate the heated backlight relay. Power is then sent to the rear window defrost grid through circuit 186 (BN/LB) from the heated backlight relay. The rear
window defrost grid is grounded to the chassis through circuit 1205 (BK).
Possible Causes
Inoperative ICM.
Inoperative DATC or manual climate control assembly.
Inoperative heated backlight relay.
Open in circuits 185 (BK), 688 (GY/LB), 1009 (OG/YE) or 1205 (BK).
PINPOINT TEST M: THE DEFROST SYSTEM IS INOPERATIVE
Connect a jumper wire between passenger rear window control switch C801-1, circuit 320
(RD/BK) and C801-2, circuit 882 (BN/YE) and a second jumper wire between C801-3, circuit
170 (RD/LB) and C801-5, circuit 881 (BN) harness side. The window should operate in the
up direction.
Does the window operate correctly?
L5 CHECK CIRCUITS 882 (BN/YE) AND 881 (BN) FOR AN OPEN
Ignition OFF.
Disconnect: Passenger Rear Window Motor C803.
Measure the resistance between the passenger rear window control switch C801-5, circuit
881 (BN) and passenger rear window motor C803-1, circuit 881 (BN) harness side.
Measure the resistance between the passenger rear window control switch C801-2, circuit
882 (BN/YE) and passenger rear window motor C803-2, circuit 882 (BN/YE) harness side.
Are the resistances less than 5 ohms?
Yes
INSTALL a new passenger rear window motor. REFER to Window Glass —
Rear Door in this section. TEST the system for normal operation.
No
REPAIR circuit 881 (BN) or circuit 882 (BN/YE). TEST the system for normal
operation.
Test Step Result / Action to Take
M1 CHECK THE POWER TO THE HEATED BACKLIGHT RELAY
2003 Explorer/Mountaineer Workshop Manual
http://www.fordtechservice.dealerconnection.com/pubs/content/~WS3N/~MUS~LEN/19/S
To Next Page
Loading...
