Ford Fusion: Horn / Horn - System Operation and Component Description. Description and Operation
System Operation
System Diagram

| Item |
Description |
| 1 |
BJB |
| 2 |
Horn Relay |
| 3 |
Horn Switch |
| 4 |
Clockspring |
| 5 |
SCCM |
| 6 |
BCM |
| 7 |
Horn |
Horn Operation
The
horn switch consists of 2 sets of contacts separated by springs. The
lower set is connected to ground and the upper set is connected to the
horn signal circuit. When the driver airbag is pressed, it pushes down
on the upper set of contacts, collapsing the springs and allowing the
contacts to touch. When the contacts touch, it completes the circuit and
provides the ground signal, which is routed through the clockspring to
the SCCM and BCM. The BCM grounds the horn relay coil to energize the integrated relay in the BJB. When energized, the horn relay provides voltage to the horn, enabling the horn to sound.
DTC Chart
Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices. REFER to: Diagnostic Methods (100-00 General Information, Description and Operation)...
Other information:
Special Tool(s) /
General Equipment
8 mm Drill Bit
MIG/MAG Welding Equipment
Spot Weld Drill Bit
Locking Pliers
Materials
Name
Specification
Seam SealerTA-2-B, 3M™ 08308, LORD Fusor® 803DTM
-
Removal
NOTICE:
Battery electric vehicle (BEV), hybrid electric vehicle
(HEV) and plug-in hybrid electric vehicle (PHEV) contain a high-voltage
battery..
Special Tool(s) /
General Equipment
Knife
Removal
NOTICE:
Under no circumstances should the accessory drive belt,
tensioner or pulleys be lubricated as potential damage to the belt
material and tensioner damping mechanism will occur. Do not apply any
fluids or belt dressing to the accessory drive belt or pulleys.
With the vehicle in NEUTRAL, position it on a hoist.
Re..