Causes of Simplicity Lawnmower Blades Not Engaging or Starting

If you can’t get your mower’s blades to spin, check the mower deck and any attachments for obstructions that could prevent power from reaching the clutch.

When the battery is low, the PTO switch or safety switch is broken, the clutch is broken, or the deck belt, pulley, tensioner bracket, or tensioner spring are worn, the Simplicity mower will not engage or turn on.

Before making any repairs, take out the ignition key and spark plug boots. You must hold off until every moving part has stopped. For further safety measures, please refer to your Simplicity operator’s manual.


Before diagnosing, repairing, or operating, be sure you’ve read and understood all of the safety recommendations in the equipment’s operator’s manual. If you don’t feel confident in your ability to conduct the repair safely due to a lack of experience, training, or health, it’s best to call in an expert.

Trouble Starting or Engaging Simplicity Lawnmower Blades

In the event that your simplicity has an electric clutch, check to see that it is receiving electricity. The battery, safety switch, PTO switch, and fuse must all be examined.

If your clutch requires manual engagement, inspect the clutch cable, lever, linkages, and bushings.

Simplicity Mower Battery Weakness

The battery is what powers an electric clutch. Low battery power prevents the clutch solenoid from activating the mower’s blades.

Inspect the battery’s voltage with a multimeter. You should see around 12.7 volts from a fully charged 12-volt battery.

If the readout is lower than this, it’s time to charge the battery. In 5 Things That Are Draining the Life of Your Lawn Mower Battery, you’ll uncover the most common causes of a dying battery and how to fix them.

To charge a Simplicity battery, you should use a battery charger. Put on safety glasses and gloves to guard against electrical shock before proceeding. Here’s how to use a charger for your riding mower or zero-turn mower’s battery:

  • Get at the terminals and batteries. To get to the battery, you might need a screwdriver. The battery is either underneath the seat or in the engine compartment. Keep the battery inside its case at all times.
  • Start by plugging in the positive cable to the battery charger. That’s the plus-sign cable, often known as the red one.
  • Connect the cable to the battery’s positive pole.
  • Join the negative end of the cable to the battery’s negative post. This is the negative-sign cable, sometimes known as the black cable.
  • To avoid electrocution, avoid touching anything that isn’t covered in rubber.
  • Alter the charger’s settings to suit your needs in terms of voltage and current. Most lawn mower batteries have 12 volts of power. More amperage means a quicker battery charge. The recommended starting point is 2 amps, with a maximum of 10 amps. It’s best to charge slowly.

If the battery isn’t holding a charge, you’ll need to get a new one. You can find batteries for a lawn mower that run on 12 volts at any home improvement or auto parts store. Local retailers of Simplicity mowers might also have batteries.

Don’t forget to bring the dead batteries. If you don’t bring in your old battery, most stores will charge you a core fee. If you don’t bring back your old battery, you’ll have to pay a core fee of about $20.

Simplicity Mower PTO Switch Failure

A Simplicity mower’s PTO switch is a knob that, when turned, allows battery voltage to operate the mower’s clutch. A broken switch means no fan will spin.

Make sure the switch has good continuity. In place of a toggle, you can use a continuity break instead.

A Simplicity Lawnmower with a Defective Safety Switch

The Simplicity’s operator presence system includes a seat-mounted safety switch. When the operator is seated, they activate the switch located under the seat.

The lawn mower’s blades are equipped with a safety feature that prevents them from starting unless the operator is there. Leaving the seat with the blades engaged will cause them to automatically shut off.

The operator may not be detected if the seat switch is defective. When a faulty seat switch is detected, the safety system will prohibit the blades from starting.

If you suspect a faulty seat switch, you can either test it with a multimeter or temporarily disable the safety switch. Please don’t risk your life by using a mower if the safety switch isn’t in place.

Make sure that your machinery has functioning safety switches at all times.

Simplicity Lawnmower Fuses Blown

A blown fuse could be to blame when the clutch isn’t receiving electricity from the battery. The Simplicity electrical system is safeguarded by the fuse.

Use another fuse of the same amperage to replace a blown one. If you keep having electrical problems with your mower, I suggest taking it to a Simplicity service dealership or a lawn mower repair shop.

The Manual Clutch Cable, Lever, and Linkage Wear on a Simplicity

Manually engaging the clutch on a Simplicity mower is done via a lever and cable

To ensure that the clutch is being engaged and that its components are not worn, check the condition of the clutch lever, cable, spring, bushings, and linkages.

Fix any broken or worn items.

Simplicity Mower Clutch Failure

By engaging the drive belt, the PTO (Power Take Off) clutch transmits power from the engine to the blades. When a worn or broken clutch can’t turn the blades, it needs to be replaced.

Simplicity Mower with Deck Belt Loosened

Check the belt on the mower deck if the blades are stuck and won’t spin. The belt that drives the mower blades can wear out and stop working.

bad or worn A deck belt is considered simple if it shows no signs of cracking, wear, fraying, or glazing. It is also possible for a deck belt to sink all the way into the pulley grooves if it has seen better days.

To fix a belt that has worn out, just replace it. When the belt shows symptoms of wear, you should replace it regardless of whether this is the primary cause of your blades not engaging.

The belt’s hold on the pulleys dictates how quickly the blades spin. To create suction under the deck and raise the grass for an even cut, a high blade speed is necessary.

Simplicity Lawnmower Idle Arm and Spring Wear

Idler pulley alignment is maintained using a tensioner arm and spring. Mower decks often have the pulley on one side of the bracket and the spring on the other.

It is possible for the spring’s attachment hole in the bracket to wear out, or for the spring itself to get worn. The belt may become unfastened, vibrate, and fall off the pulleys as a result.

A Simplex Pulley With a Worn Bearing

Each pulley features an integral bearing. When the pulley’s bearing wears out, it might cause the shaft to angle away from the mower’s deck. The pulley will wobble due to the worn bearing allowing rotational movement.

It’s possible that the pulley’s deck mounting is uneven. The deck belt may become dislodged from the pulley as a result of the increased rotation.

If the bearing in a Simplicity pulley is worn out, you ought to substitute it.