CAMPAIGN: PUSH-PULL HEADLIGHT SWITCH DEFECTIVE. GMC Truck S15 Pickup - 2WD 1985

For 1990-2009 cars

# CAMPAIGN: PUSH-PULL HEADLIGHT SWITCH DEFECTIVE

#### MODELS: 1985 S/T15 AND P25-35 MODEL LIGHT DUTY TRUCKS 1986 C/K, G VAN, MEDIUM DUTY, AND HEAVY DUTY MODEL TRUCKS

The following information supplements the "Vehicles Involved" and the "Inspection Procedure" portions of Campaign Bulletin 86-C-04. Please update your Bulletin accordingly.

#### VEHICLES INVOLVED

In addition to the vehicles specified in Bulletin 86-C-04, the following units should be induded.

#### Model Year Model Plant From Through ---- ------ ----- ---- ------- 1986 P3 Detroit Assembly G3502163 G3502553 GVan Scarborough G4518889 G4520570 Lordstown G7511905 G7512484 C/K Janesville GJ521261 GJ522642 Flint #1 GF721388 GF722421 Flint #2 GF520150 GF521445 St. Louis GS520961 GS522584 Oshawa G1527436 G1529915

#### INSPECTION PROCEDURE

1986 GMC vehicles indicated above require a different inspection procedure from that described in Dealer Product Campaign Bulletin 86-C-04. If the alphabetically marked headlight switch cavity has either a "D" or an "M" identified, the switch must be replaced. The headhght switch cavity is on the opposite side of the switch from the date code indicated in 86-C-04.

1. After removing the headlight switch from the instrument panel, refer to the illustration to locate and identify the cavity code.

2. If the cavity code is a "D" or an "M" replace the switch using the correct part number in the Parts Information section. If the switch does not have "D" or "M" codes, reconnect the existing switch.

3. Install the Campaign Completion label on a clean dry surface of the radiator core support.

Dear GMC Truck Owner:

This notice is sent to you in accordance with the requirements of the National Traffic and Motor Vehicle Safety Act.

General Motors has determined that a defect which relates to motor vehicle safety exists in some 1985 S/T15 and P25-35 model light duty trucks and 1986 G van and C/K trucks.

The push-pull headlight switch might have been manufactured with electrical contacts which allow an intermittent headlight circuit. An intermittent circuit could cause the headlights to flicker or suddenly go out. Sudden loss of the headlights under severe weather or nighttime driving conditions could reduce driver visibility which might result in a vehicle crash without prior warning.

Until you have had an opportunity to have your GMC truck corrected, you should be alert for signs of an intermittent headlight circuit. For example, you might experience flickering headlights or temporary delay when you pull the headlight switch "ON", or the headlights might not light at all. If you experience one of these conditions, a gende upward pressure on the headlight knob may light the headlights.

To prevent this, please contact your GMC Truck dealer on or after the date shown below to arrange a service date to have your vehicle inspected. Your dealer will check the headlight switch. If necessary, the switch will be replaced. This service will be completed at no charge to you.

Instructions have been sent to your GMC Truck dealer. It is estimated that parts will be available to your dealer on October 1, 1986. The labor time necessary to check the headlight switch and replace it, if necessary, is 35 minutes. Please ask your dealer if you wish to know how much additional time will be needed to process your vehicle.

Your GMC Truck dealer is best equipped to obtain parts and provide service to ensure your vehicle is corrected as promptly as possible. However, if you take your vehicle to your dealer on the agreed service date and they do not remedy this condition on that date or within five days, we recommend you contact your nearest GMC Truck Zone Office, either in person or by telephone. The Zone Office will assist you and your dealer in getting your vehicle corrected. The locations and telephone numbers of the Zone Offices are listed in your Owner's Manual.

After contacting your dealer and the Zone Office, if you are still not satisfied that we have done our best to remedy this condition without charge within a reasonable time, you may wish to write the Administrator, National Highway Traffic Safety Administration, 400 Seventh Street S.W., Washington, D.C. 20590, or call 800-424-9393 (Washington, D.C. residents use 426- 0123).

The enclosed owner reply card identifies your vehicle. Presentation of this card to your dealer will assist them in making the necessary correction to your vehicle in the shortest possible time. If you have sold or traded your vehicle, please let us know by completing the postage paid owner repty card and returning it to us.

We are sorry to cause you this inconvenience, however, we have taken this action in the interest of your safety and confinued satisfaction with our products.

GMC TRUCK GENERAL MOTORS CORPORATION

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.