2-Pack Seat Safety Switch 430-690 for Lawn Mower – NC & NO Interlock Switch Compatible with John Deere AM104403, MTD 925-3166, AYP 121305X – Fits Toro, Murray, Scag, Craftsman, Kubota, Simplicity

What It Is

This 2-pack of seat safety switches (part 430-690) is a universal replacement for lawn mower operator-presence systems. It cuts the engine or prevents starting when the operator leaves the seat, working across riding mowers, zero-turns, and garden tractors from major brands like John Deere, MTD, AYP, Toro, Murray, Scag, Craftsman, Kubota, and Simplicity.

Fitment & Compatibility

Before buying, confirm your mower’s switch type: this pack includes one Normally Closed (NC) and one Normally Open (NO) switch. Check your original switch’s wiring diagram—if your mower uses a single NC or NO switch, you’ll have one spare. Measure the switch’s mounting hole spacing (typically 1.5” center-to-center) and the plunger length (standard ~0.5”). Cross-reference OEM part numbers: John Deere AM104403, MTD 925-3166, AYP 121305X. Not compatible with switches that have different terminal layouts (e.g., 3-prong vs. 2-prong) or unusual plunger travel distances. Verify your mower’s model number via the manufacturer’s parts lookup.

Key Things to Know

• Quality: Aftermarket, budget-friendly. Some users report shorter lifespan than OEM, but sufficient for occasional use. Test continuity with a multimeter before installation.
• Installation: Easy—disconnect battery, unplug old switch, remove mounting screws, reverse steps. No special tools needed. Pay attention to wire routing to avoid pinching.
• Common Gotcha: Mowers with dual switches (e.g., some Kubota or Simplicity models) may require both NC and NO—this pack covers that. Single-switch mowers will leave one unused.
• Fitment Note: Plunger length and actuation force vary slightly across brands. If the switch doesn’t click firmly when seated, adjust the bracket or shim with a washer.

Should You Buy It

Buy this 2-pack if you need a quick, affordable fix for a failing seat switch on a mid-range or older mower and are comfortable with basic electrical testing. Skip it if you want OEM reliability for heavy commercial use, or if your mower uses a unique switch configuration (e.g., integrated with seat belt sensor).