HORN Fuse
Location: Underhood Fuse Block
Type: 15 amp mini fuse
Feeds: CKTs 28 and 29 of the horn relay
This fuse feeds only the horn relay. If the fuse is blown determine the cause of the blown fuse and repair. Replace fuse as needed.
Grounds
Before checking the ground circuit from the faulty component all the way to the ground stud, check the circuit from the splice pack to ground by testing some of the other subsystems grounded by the same splice pack. If the other subsystems function properly, the path from the splice pack-to-ground is good.
Ground: 150
Location: Horn connector cavity 2 to forward lamp ground splice pack cavity G
Important: Due to manufacturing process for splice packs the cavity shown on the schematics may not match the harness.
If the following circuits are operating normally, the ground is most likely good.
| • | Side Marker Lamps |
| • | Park/Turn Lamps |
| • | Cooling Fan Module |
| • | Auxiliary Pump |
| • | Fog Lamps |
| • | Low Washer |
Check for OPENS/SHORTS. Repair as needed
Ground: 550
Location: Connects horn switch through the LIPFB cavity A1 through the roll connector cavity E.
If the following circuits are operating normally, the ground is most likely good.
| • | Trunk Release |
| • | Wipers |
| • | Glove Box Lamp |
| • | HVAC |
| • | Headlamp Switch |
Check for OPENS/SHORTS.
Repair as needed
Power Circuits
CKT 28
Location: Connects UHFB I/P connector cavity A3 to base of column connector cavity F and to BCM cavity J3-B2
Function: This circuit provides ground for the horn relay coil. The relay coil is grounded when the horn switch is closed -- the horn pad is depressed -- or when commanded by the BCM.
Check for OPENS/SHORTS.
Repair as needed
CKT 29
Location: Connects UHFB Forward Lamp connector cavity D4 to horn connector cavity 1.
Function: This circuit provides power to the horn.
Check for OPENS/SHORTS.
Repair as needed
Components
Horn Relay
Find a relay that is interchangeable with the horn relay to see if this fixes the horn circuit.
Repair/Replace as needed.
SIR/Cruise/Turn Coil Assembly
Check resistance through the coil assembly by measuring voltage at horn switch and rotating steering wheel.
Check for OPENS/SHORTS in cavities E and F.
Repair as needed
Horn Switch
Check resistance through horn switch. The switch resistance should be less than one ohm when the horn pad is depressed and open when the horn pad is not depressed.
Check for OPENS/SHORTS.
Repair as needed
Horn
Check resistance through the horn. Horn resistance should be 2-4 ohms.
