Standard Ignition NS-120 Clutch Starter Safety Switch

Clutch Starter Safety Switch for GM Applications

The Standard Ignition NS-120 clutch starter safety switch is built for GM trucks and SUVs that use a 4-blade terminal configuration. It helps restore proper starter interlock operation on many Chevrolet and GMC models, including C/K series trucks, Suburban, Blazer, Jimmy, and Yukon applications.

• Female connector gender with 2 connector cavities
• Male blade terminals with 4 terminal positions
• Built with copper alloy conductors for strong electrical conductivity
• 100% tested for mechanical and electrical switching performance
• Direct-fit service part for select Chevrolet and GMC manual-transmission starter safety switch applications

Fitment and Application Details

Compatible with a wide range of Chevrolet and GMC vehicles from 1985-2003, including 1985-1986 Chevrolet C10, K10, C20, K20, C30, K30, and K5 Blazer; 1987 Chevrolet R10, R20, R30, V10, V20, and V30; 1988-1991 Chevrolet C1500, C2500, C3500, K1500, K2500, K3500, R20, R30, V30, and related Suburban models; and 1997-2000 Chevrolet C1500, C2500, C3500, K1500, K2500, K3500, plus 1999-2000 Chevrolet C1500 and K1500. It also fits 1985-1991 and 1996-2003 GMC Jimmy, 1985-1986 and 1997-1999 GMC C/K trucks, 1985-1986 and 1992 GMC Suburban models, 1987-1991 GMC R/V series trucks and Suburbans, and 1992 GMC Yukon.

This part cross-references Standard Ignition NS449 and NS5543 for the same application.

What This Switch Helps Resolve

• No-crank condition caused by a worn clutch starter safety switch
• Starter engagement issues when the clutch interlock circuit is inconsistent
• Intermittent electrical switching from heat, wear, or corrosion at the switch
• Starting problems on Chevrolet C/K trucks and GMC Jimmy or Suburban models with the correct connector style
• Restoration of proper clutch-start safety circuit operation after switch failure

Installation Notes and Quality Assurance

Verify connector style, terminal count, and vehicle application before installation. This NS-120 uses a female connector with 2 cavities and 4 male blade terminals, so matching the original configuration is important for proper operation. Standard Ignition builds this switch with robust materials and tests each unit for mechanical and electrical performance to support reliable service in demanding repair environments.

Standard Ignition NS-120 is engineered for consistent switching performance and dependable electrical contact in service applications.