1966 Corvette: Engineering Service Letter: RPO K-66 Wiring Diagram for Breakerless Ignition System
This Chevrolet Engineering Service Letter contains important information for all owners of 1966 Corvettes that are equipped with the RPO K-66 transistorized ignition system. Original 1966 Corvette shop manuals do not have this information.
Subject: RPO K-66 Wiring Diagram for Breakerless Ignition System
Model and Year: 1966 Chevfrolet, Chevelle, Chevy II, and Corvette with RPO K66
Source: Chevrolet Engineering Service Bulletin
Bulletin No: TSB #11
Date: November 11, 1965
With reference to the 1966 Passenger Car Chassis Service Manual, Section 6Y-15, the wiring diagram of Figure 3.i requires clarification. The diagtram on the left side of Figure 3.i should be titled "Chevrolet, Chevy II, and Chevelle" and the right side diagram should be titled "Corvette" (see attached.)
On the Corvette diagram, the "12 white" wire and the "20 black" wire from the negative ignition coil terminal to ground on the pulse amplifier should be an "18 black" wire for its entire length. The "12 white" is a calibrated resistance wire and is located on the negative side of the ignition coil on 1965 vehicles. However, in 1966 this resistance was placed on the positive side of the coil for added protection of the pulse amplifier in the event of accidentally grounding the ignition coil wire. This change has been incorporated in the passenger car models only.
The pulse amplifier in the left side view of the figure should reflect that the unit is grounded.