GM Service Manual Online
For 1990-2009 cars only

The current draw for a horn while operating should be 4.5-5.5 amperes at 11.5-12.5 volts. Review the following common conditions:

    • A high current of more than 20 amperes indicates an overheated winding or indicates a shorted horn. Replace the horn.
    • A current reading of about 18 amperes means the contact points are not opening. Adjust the horn.
    • No current reading indicates one of the following:
      • A broken connection.
      • An open circuit due to a broken lead.
      • An open circuit due to an overheated horn.
      • The contact points are open. Adjust the horn.

Perform the necessary step to adjust the current:

    • Turn the adjustment screw clockwise 1/4 turn (90°) at a time to increase the current.
    • Turn the adjustment screw counterclockwise 1/4 turn (90°) to decrease the current.