F 350 2WD Super Duty V8-6.4L DSL Turbo (2009)
Horn: Initial Inspection and Diagnostic Overview
Special Tools Used With Diagnostics
Horn
Inspection and Verification
Horn
Inspection and Verification
1. Verify the customer concern.
2. Visually inspect for obvious signs of mechanical or electrical damage.
Visual Inspection Chart
Visual Inspection Chart
Principles of Operation
Horn
Principles of Operation
NOTE: The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).
The SJB supplies the switched and control voltage to the horn relay (part of the SJB). When the horn switch (part of the driver air bag module) is
pressed, ground is supplied to the SJB through the clockspring. The SJB then energizes the horn relay sending voltage to the horn, enabling the horn to
sound.
The SJB provides a momentary ground to the horn relay when the anti-theft system is armed, and an on then off ground when the panic button is pressed
