Ford 2003 Mustang Workshop Manual page 3879

Connect a fused jumper wire (30A) between wiper
HIGH/LOW relay Pin 30, Circuit 61 (YE/RD), harness side
and Pin 87, Circuit 58 (WH), harness side.
Did the wiper motor speed increase with the jumper
installed and slow down with the jumper removed?
B18 CARRY OUT COMPONENT TEST ON WIPER HIGH/LOW
RELAY
Check the wiper HIGH/LOW relay; refer to Wiring
Diagrams, Cell 149, Component Testing.
Is the wiper HIGH/LOW relay OK?
B19 CHECK CIRCUIT 647 (GY/LB) FOR SHORT TO
BATTERY BETWEEN GEM AND BJB
Disconnect: GEM C201d.
Measure voltage between GEM C201d Pin 5, Circuit 647
(GY/LB), harness side and ground.
Is the voltage greater than 10 volts?
B20 CHECK CIRCUIT 647 (GY/LB) FOR SHORT TO GROUND
BETWEEN GEM AND BJB
Measure the resistance between GEM C201d Pin 5,
Circuit 647 (GY/LB), harness side and ground.
GO to B18 .
No
GO to B26 .
Yes
GO to B19 .
No
INSTALL a new wiper
HIGH/LOW relay. REPEAT
the self-test. CLEAR the
DTCs.
Yes
REPAIR Circuit 647 (GY/LB).
REPEAT the self-test.
CLEAR the DTCs.
No
GO to B20 .
Yes
GO to B21 .
No
REPAIR Circuit 647 (GY/LB).
REPEAT the self-test.
CLEAR the DTCs.