GM Service Manual Online
For 1990-2009 cars only

Object Number: 371792  Size: SH

The current draw for an operating horn should be 4.5-5.5 amperes at 11.5-12.5 volts. High current (more than 20 amperes) indicates the following conditions.

Replace the horn if any of these conditions exist:

    • Overheating
    • Winding
    • Short

Important: 

   • Rotate the adjusting screw (2) clockwise in order to increase the current.
   • Rotate the adjusting screw  (2) counterclockwise in order to decrease the current.
   • The limit is 4.5-5.5 amperes at 12 volts.
   • Make adjustments in ¼ turn intervals.

If the current reads about 18 amperes, the contact points are not opening. Adjust the horn current under this condition.

No current reading indicates one of the following conditions:

    • A broken connection
    • An open circuit due to a broken lead (3)
    • An open circuit due to an overheated horn
    • The contact points are open

Replace an overheated horn. Adjust the horn if the contact points are open.