Bench Checks

^ Measure current draw of horn while horn is operating. Current draw for each horn should be between 4.5 A and 5.5 A at 11.5 to 12.5 volts.
^ No current may indicate a broken connection or an open circuit due to a broken lead or overheating. Most horn problems are caused by horns being operated continuously, developing sufficient heat to melt the wires in the winding, causing an open circuit.
^ No current can also indicate that the contact points are open and a current adjustment is required.
^ High current, over 20 A, indicates a shorted horn which should be replaced.
^ A reading of approximately 18 A for a 12-volt horn indicates a condition in which the contact points are not opening. A current adjustment is required.