PHANTOM WIPE/LACK PULSE MODE WATER IN BULKHEAD CONNECTOR

VEHICLES AFFECTED: 1988 C/K TRUCKS EQUIPPED WITH PULSE WIPERS (RPO CD4)

On some 1988 C/K trucks equipped with pulse wipers (RPO CD4), the windshield wipers will sweep the windshield even though the windshield wiper switch is in the off position. A loss of delay variability may also occur.

Phantom wipe and lack of pulse mode wipe may occur because of water in the bulkhead connector located in the engine compartment. To eliminate these phenomena, the bulkhead connector must be dried out and resealed with grease to prevent further water contamination.

The following procedure may be used to repair this condition.

Disconnect negative battery cable.

Locate bulkhead connector for the instrument panel harness on the left side of the cowl panel, figure 1. Unsnap the three outer harness covers from the connector and separate the connector halves by unscrewing the bolt in the center of the connector.

Remove all grease from both sides of the connector using a petroleum based solvent such as naphtha or mineral spirits. Blow dry both sides of the connector to remove remaining grease and any moisture using filtered compressed air.

Apply a heavy coat of lube P/N 1052497, 1051344 or petroleum jelly to the half of the connector mounted on the cowl. Fi 11 all cavities. Apply lube to the mating half of the connector ensuring all terminal blades are covered.

Reconnect connector halves. Apply lube to the outside face of the connector and at wire entry. Reinstall covers.

Clean engine compartment as required to remove all excess lube.

Reconnect negative battery cable.

With engine running and the windshield washer switch in the off position, spray water from a hose on the connector. The wipers should not sweep the windshield. If they do, repeat the entire procedure.

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.