Ford 2003 Mustang Workshop Manual page 3739

H4 CHECK CIRCUIT 175 (BK/YE)
Disconnect: ICM C220a.
Key in ON position.
Measure the voltage between ICM C220a pin 9, circuit 175
(BK/YE), harness side and ground.
Is the voltage greater than 10 volts?
H5 CHECK CIRCUIT 175 (BK/YE) FOR A SHORT TO POWER
Disconnect: Rear Window Defrost Switch C241.
Measure the voltage between rear window defrost switch
C241 pin 2, circuit 175 (BK/YE), harness side and ground.
Is the voltage greater than 10 volts?
H6 CHECK THE REAR HEATED WINDOW GRID POWER
Disconnect: Heated Rear Window Grid Power Supply
Connector C402a.
Key in ON position.
Depress the rear window defrost switch to ON.
Measure the voltage between heated rear window grid
C402a circuit 186 (BN/LB), harness side and ground.
Is the voltage greater than 10 volts?
H7 CHECK THE REAR WINDOW GROUND
Key in OFF position.
No
GO to H6 .
Yes
GO to H5 .
No
GO to H16 .
Yes
REPAIR the circuit.
CLEAR the DTCs.
REPEAT the self-test.
No
INSTALL a new rear
window defrost switch.
REFER to Rear Window
Defrost Switch in this
section. TEST the system
for normal operation.
Yes
GO to H7 .
No
GO to H8 .
Yes