A tachometer needs a clean signal from the ignition to read accurately, and a spliced feed is a common cause of a needle that wanders. This harness supplies that circuit with correct connectors and wire.

American Autowire 10150 Technical Specifications:

• Application: 1966 Oldsmobile Cutlass.
• 6 cylinder.
• Correct wire colors and factory style terminals for straightforward circuit tracing.
• Sold individually.