How to Bypass a Lawn Mower Key Switch

Riding mowers almost always come equipped with starter keys. This is for safety reasons, but it also helps to prevent theft. However important safety may be to you, there may occasionally come a time where you have lost or broken the key switch on your riding lawn mower, and need to turn it on through an alternate method. The most important thing to remember when hot-wiring anything is safety. Make sure you have all of the tools that you will need before you begin. Battery safety is extremely important.

Mowing the grass
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How to Bypass a Lawn Mower Key Switch

Riding Mower Key Switch

Your riding mower key switch key works because it creates an electrical connection between your riding mower's solenoid and the mower's starter. The key has a metal bit that touches both poles, sending electricity across the solenoid into the starter and turning on the mower's motor. If the key has broken off or been lost or is otherwise unable to perform that critical function, you will need to find a way to mimic the action and behavior of the starter key in order to get the mower on and running.

Starting the Mower with Jumper Cables

You will need a pair of rubber gloves, jumper cables, battery post cleaners and a pair of pliers. Rubber gloves are very important. Rubber prevents electrical current conduction, keeping you safe from any electrical shock from the battery. Do not attempt to bypass the mower's key switch if you do not have rubber gloves.

  1. Put on rubber gloves.
  2. Make sure the brake is ON, the blade is disengaged and all other safety precautions are put into effect so that the tractor cannot move forward without you releasing it
  3. Open the hood of the riding mower
  4. Find the battery
  5. Disconnect the red and black cables from the two electrical posts in the solenoid
  6. Using a battery post cleaner clear off any dirt or corrosion that might have accumulated on both of the posts.
  7. Reconnect both cables.
  8. Clamp the black booster cable around the riding mower's negative battery post, and clamp the other end to the metal deck on the mower.
  9. Clamp the red cable to the positive battery post on the riding mower, and then still wearing your rubber globes, touch the other end of the red cable to the metal piece on the mower's starter.
  10. When the engine turns over, remove the red booster cable, then the black booster cable. Finally, cose the engine hood.

Starting the Mower with a Screwdriver

If the two electrical posts you need to engage—one on the solenoid, the other on the starter—are very close together, you can put on your rubber gloves then touch a screwdriver to both of the posts and the engine should start.


Ashley Friedman

Ashley Friedman

Ashley Friedman is a freelance writer with experience working in the home, design and interiors space.