1979 Corvette: Service News: Corvette Auxiliary Cooling Fan Wiring Revision

Subject: Corvette Auxilliary Cooling Fan Wiring Revision
Model and Year: 1979 Corvette Equipped with 5.7L (350 Cu. In.) V-8 RPO L82 and Air Conditioning
Source: Chevrolet Service News
Page Number:   3
Date: Volume 51, Number 1

Corvettes equipped with the L82 engine plus air conditioning use an auxiliary  cooling fan to pull additional air through the radiator and air conditioning condenser.  Power to the fan motor is supplied through the ignition switch and a thermostatic switch which controls fan operation.

During early production, it was discovered that non-powered rundown of the fan motor generated a voltage sufficient to maintain ignition after ignition switch shut-off.  This could result in a momentary engine run-on condition similar to dieseling.

To eliminate any run-on, the assembly plant began re-working the instrument panel wiring harness, effective with VIN 1Z8749S402690, as shown in the wiring diagram (see Figure 4).  A final production revision to the harness (see diagram) will be phased into production as soon as possible.