121305X Seat Switch 430-690 7023354YP Compatible with John Deere AM104403 AYP 121305X Scag 48717 MTD 925-3166 Toro 740275 Murray 094159MA Simplicity 1714770SM Troy Bilt 1761083 Lawn Mower

What It Is

This is a replacement seat safety switch (also called a seat interlock switch) for lawn tractors and zero-turn mowers. It disables the engine or blade engagement when the operator leaves the seat, preventing accidents.

Fitment & Compatibility

• Cross-references: Fits John Deere AM104403, AYP 121305X, Scag 48717, MTD 925-3166, Toro 740275, Murray 094159MA, Simplicity 1714770SM, Troy Bilt 1761083. Also replaces OEM part 430-690 and 7023354YP.
• Check your current switch: Measure the mounting hole spacing (typically 1.5" center-to-center) and the plunger length (usually about 0.75"). This switch has a 2-wire flat blade connector.
• Verify connector type: This is a normally-open (NO) switch—pressing the plunger closes the circuit. If your mower uses a normally-closed (NC) switch, this won’t work.
• Not universal: Some zero-turn or older tractors may use a different plunger shape or mounting bracket. Compare visually with your old switch.

Key Things to Know

• Quality: Solid aftermarket build, but the plastic housing can crack if over-tightened. Use hand-tightening only.
• Installation: Simple—unplug the old switch, remove the retaining clip or screw, install the new one, and reconnect. No wiring cutting needed.
• Common gotcha: If your mower still won’t start after replacement, check the wiring harness for corrosion or a broken wire near the seat. Also ensure the safety relay is not faulty.
• Testing: Use a multimeter to confirm continuity when the plunger is pressed. If the switch tests fine but the mower won’t start, the issue is elsewhere in the safety circuit.

Should You Buy It

Yes, if you need a direct replacement for a failed seat switch on a common residential or light-commercial lawn tractor. It’s inexpensive, easy to swap, and covers a wide range of brands. Skip it if your mower uses a different connector or switch type (e.g., NC or 3-pin).