Section 1623 (Horn System - (Service Information) - 2500 Hd): Horn: Description
Dual electromagnetic diaphragm-type horns are standard equipment on this vehicle. A low note (2) and a high note (1) trumpet-style horn are each secured to a mounting bracket (3). The horn and mounting bracket unit is then secured by a single screw to the outboard-facing surface of the left upper fender load beam above the left front wheel opening. Internally the two horns are identical in construction and the external horn trumpets are symmetrically opposite.
A short jumper harness connects the horns to each other electrically so they can both be connected through a single connection (4) integral to the rearward horn. A dedicated take out and connector of the headlamp and dash wire harness connects the horns to the vehicle electrical system.
The two horns and the mounting bracket are factory-tuned as a unit and, therefore, are serviced only as a unit. These horns cannot be adjusted or repaired. If either horn or the mounting bracket is ineffective or damaged, the entire unit must be replaced.