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1990 - 1991 Corvette: Service Bulletin: Intermittent Electrical Conditions - Repair/Diagnosis Procedures

Model and Year: 1990-91 CORVETTE
Source: Chevrolet Service Bulletin
Bulletin Number: 91-337-6D - (05/30/1991)


The electrical system on the 1990-91 Y Car may have one or more intermittent electrical conditions that are very difficult to diagnose. These conditions are often related to engine electrical operation, and may or may not set codes.


The engine electrical harness may be rubbed thru by the mounting clamp just below the oil pressure sensor (see illustration). The conduit covering the harness may be positioned so that the tab on the clamp can enter the harness thru the slit, allowing the clamp to contact the wires, which are then rubbed thru with the normal movement of the engine.


1. Disconnect negative battery cable.

2. Remove windshield wiper motor.

3. Remove harness from clamp. Carefully inspect the wires for rub thru spots, and correct the damage as necessary.

4. Wrap the harness with electrical tape. Replace the conduit, then overwrap the outside of the harness with more electrical tape. Secure the harness to the clamp so that the tab cannot enter the harness.

5. Replace the wiper motor.

6. Reconnect negative battery cable.

Warranty Information

Labor Operation: T1742 Labor Time: .9 Hour Trouble Code: 92

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.

© Copyright General Motors Corporation. All Rights Reserved

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