HomeElectrical, Lighting and Body > SwitchesStandard Ignition NS-121 Clutch Starter Safety Switch
Part #: NS-121

Standard Ignition NS-121 Clutch Starter Safety Switch

⚙️ 46 vehicles fit this part
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OE Direct Replacement — Bolt-on fit, no modifications needed
🚗Fitment: Cadillac, Chevrolet, GMC, and Isuzu, CTS, Blazer, S10, Sonoma, Hombre, C1500, C2500, C3500, K1500, K2500, and K3500
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Reliable Clutch Starter Safety Switch for Select GM and Isuzu Vehicles

The Standard Ignition NS-121 clutch starter safety switch is designed to ensure safe engine starting by preventing the vehicle from starting unless the clutch pedal is fully depressed. This black plastic switch features a female connector and four male blade terminals, engineered for durability and precise fitment.

Key Features of the Standard Ignition NS-121 Switch

  • Color: Black plastic housing for corrosion resistance
  • Connector Gender: Female with one connector for secure wiring
  • Terminal Type: Four male blade terminals for reliable electrical contact
  • Finish: Durable plastic construction for long-lasting performance
  • Compatible with multiple GM and Isuzu models including Chevrolet Blazer, C1500, C2500, C3500, Cadillac CTS, GMC K1500, K2500, K3500, and Isuzu Hombre, S10, Sonoma

Detailed Product Description

The NS-121 clutch starter safety switch from Standard Ignition is engineered to meet OEM specifications for electrical and mechanical performance. Its black plastic finish provides resistance against environmental factors, while the female connector and four male blade terminals ensure a secure and stable electrical connection. This switch is essential for vehicles requiring clutch pedal engagement before engine start, enhancing safety and preventing accidental starts. It is compatible with a range of Chevrolet, Cadillac, GMC, and Isuzu models, making it a versatile replacement part for your vehicle’s electrical system.

Common Applications and Issues Addressed

  • Prevents engine from starting unless clutch pedal is depressed
  • Resolves no-start conditions related to faulty clutch safety switches
  • Eliminates intermittent starting problems caused by worn or damaged terminals
  • Restores proper electrical connection in the clutch starter circuit
  • Ensures compliance with vehicle safety starting protocols

Installation Notes and Tips

  • Verify vehicle compatibility with Chevrolet Blazer, C1500, C2500, C3500, Cadillac CTS, GMC K1500, K2500, K3500, Isuzu Hombre, S10, and Sonoma before installation
  • Disconnect the battery before replacing the clutch starter safety switch to avoid electrical shorts
  • Ensure the female connector and male blade terminals are clean and free of corrosion for optimal connection
  • Test clutch pedal engagement and engine start function after installation

Quality Assurance and Warranty Information

Standard Ignition parts are manufactured to meet or exceed OEM standards, ensuring reliable performance and fitment. The NS-121 clutch starter safety switch undergoes rigorous quality control to maintain durability and electrical integrity. Warranty coverage details should be confirmed with the product documentation or supplier.

BrandStandard Ignition
Part NumberNS-121
ColorBlack
Connector GenderFemale
FinishPlastic
Terminal GenderMale
Terminal TypeBlade

This part fits 46 vehicles. Search below:

YearMakeModelLitersCylindersPositionNotes
2007CadillacCTS2.8LV6N/A
2007CadillacCTS3.6LV6N/A
2005CadillacCTSN/A
2004CadillacCTSN/A
2003CadillacCTSN/A
2003ChevroletBlazerN/A4 Pin
2003ChevroletS10N/A4 Pin
2003GMCSonomaN/A4 Pin
2002ChevroletBlazerN/A4 Pin
2002ChevroletS10N/A4 Pin
2002GMCSonomaN/A4 Pin
2001ChevroletBlazerN/A4 Pin
2001ChevroletS10N/A4 Pin
2001GMCSonomaN/A4 Pin
2000ChevroletBlazerN/A
2000ChevroletS10N/A
2000GMCSonomaN/A
2000IsuzuHombreN/A
1999ChevroletBlazerN/A
1999ChevroletS10N/A
1999GMCSonomaN/A
1999IsuzuHombreN/A
1998ChevroletBlazerN/A
1998ChevroletC1500N/A
1998ChevroletC2500N/A
1998ChevroletC3500N/A
1998ChevroletK1500N/A
1998ChevroletK2500N/A
1998ChevroletK3500N/A
1998ChevroletS10N/A
1998GMCC1500N/A
1998GMCC2500N/A
1998GMCC3500N/A
1998GMCK1500N/A
1998GMCK2500N/A
1998GMCK3500N/A
1998GMCSonomaN/A
1998IsuzuHombreN/A
1997ChevroletBlazerN/A
1997ChevroletS10N/A
1997GMCSonomaN/A
1997IsuzuHombreN/A
1996ChevroletBlazerN/A
1996ChevroletS10N/A
1996GMCSonomaN/A
1996IsuzuHombreN/A

* Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.

This part directly replaces or is cross-referenced with the following part numbers:

115161841S510953-315548850DR4078NS222NS5547S26054

Cross-reference numbers are provided for identification purposes only. Always confirm fitment before ordering.