Wipers - Phantom Wipe or Lack of Pulse Mode

87chevy18
GMC NUMBER: 88-T-40

GROUP: 8D - Windshield Wiper/Washer System

DATE: September, 1987

CORPORATE
NUMBER: 868202
SUBJECT: PHANTOM WIPE OR LACK OF PULSE MODE WIPE

MODELS: 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. Warranty repairs should be submitted using labor operation number T7398. Time required to perform this procedure is .6 hr.

^ Disconnect negative battery cable.

FIGURE 1 - L.H. ENGINE COMPARTMENT (TYPICAL):

^ Locate bulkhead connector for the instrument panel harness on the left side of the cowl panel, Figure No. 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. Fill 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.