For 1990-2009 cars

# ROUGH ENGINE/HORN USE-VOLTAGE FEEDBACK FROM HORN COIL

A CONDITION MAY EXIST WHICH COULD CAUSE ENGINE ROUGHNESS ON EARLY 1982 EFI VEHICLES DURING HORN OPERATION. A VOLTAGE FEEDBACK FROM THE HORN COIL CAN RESULT IN IRREGULAR PULSES AT THE INJECTION UNIT. THE CONDITION CAN BE CORRECTED BY ADDING A .25 TO .5 MFD CAPACITOR BETWEEN THE HORN FEED WIRE AND GROUND AT THE HORN CONNECTION. PART NUMBER 1851428 OR EQUIVALENT MAY BE USED. INSTALLATION PROCEDURE: 1. UNPLUG HORN FEED WIRE FROM HORN. 2.ATTACH CAPACITOR BRACKET USING THE SCREW ATTACHING HORN TO FRAME. 3.PLUG MALE CONNECTOR OF CAPACITOR ONTO HORN. 4.PLUG MALE CONNECTOR OF HORN FEED WIRE INTO FEMALE CONNECTOR OF CAPACITOR. SEE ILLUSTRATION.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.