Ford 2003 Mustang Workshop Manual page 3314

connector Pin 3, Circuit 6 (component side), and air bag sliding
contact C218a Pin 2, Circuit 6 (component side).
Is the resistance less than 5 ohms?
A7 CHECK THE STEERING WHEEL SWITCH HARNESS
Inspect the steering wheel switch harness for chafing, opens or
possible short to ground.
Is the steering wheel switch harness OK?
PINPOINT TEST B: THE HORN SOUNDS CONTINUOUSLY
Test Step
B1 CHECK HORN CIRCUIT 1 (DB)
Key in OFF position.
Disconnect: Horn Relay.
Does the horn continue to sound?
B2 CHECK HORN RELAY
Check the horn relay; refer to Wiring
Diagrams Cell 149.
Is the horn relay OK?
B3 CHECK CIRCUIT 6 (YE/LG)
Disconnect: Air Bag Sliding Contact
C218a .
Does the horn continue to sound?
B4 CHECK GEM INPUT
Disconnect: GEM C201e.
Result / Action to Take
Yes
REPAIR Circuit 1 (DB) for short to battery. TEST
the system for normal operation.
No
GO to B2 .
Yes
REINSTALL the horn relay. GO to
No
INSTALL a new horn relay. TEST the system for
normal operation.
Yes
GO to B4 .
No
RECONNECT the air bag sliding contact. GO to
B5 .
Yes
No
INSTALL a new air
bag sliding contact.
REFER to Section
501-20B . TEST the
system for normal
operation.
Yes
INSTALL a new horn
switch. REFER to
Switch—Horn . TEST
the system for normal
operation.
No
INSTALL a new
steering wheel switch
harness. TEST the
system for normal
operation.
B3 .