February 1, 2015

How to replace a riding lawn mower ignition switch

By Lyle Weischwill
How to replace a riding lawn mower ignition switch

This DIY repair guide gives instructions for how to replace an ignition switch on most riding lawn mowers. If the riding mower won't start when you turn the ignition key to On or won't stop when you turn the key to Off, the ignition switch could be the problem. To check, use a multimeter to test whether electricity travels between the S and B terminals. If the ignition switch is the problem, replace it with the manufacturer-approved riding lawn mower part.

This basic procedure works for Craftsman, MTD, Murray, Toro, Troybilt, Husqvarna, Poulan, Weed Eater and Yard-Man riding lawn mowers and lawn tractors.

Quick links
Tools required
Wrench set
Work gloves
Repair difficulty
Time required
15 minutes or less
Repair difficulty
Time required
15 minutes or less
Replacing the ignition switch on a riding lawn mower

This video explains how to replace the ignition switch on a riding mower.

Instructions

  1. 01.

    Disconnect the battery

    Park the tractor on a level surface and set the parking brake.

    Turn the ignition switch off and remove the key.

    Wear work gloves to protect your hands.

    Lift the seat.

    Remove the bolt connecting the negative cable to the battery and tuck the cable away from the battery so it doesn't touch the battery post.

    PHOTO: Disconnect the battery.

    PHOTO: Disconnect the battery.

  2. 02.

    Remove the ignition switch

    Lift the hood to access the back of the ignition switch.

    Release the locking tabs and push the switch out though the front of the dash.

    Disconnect the wire harness attached to the back of the ignition switch; if it's difficult to unplug, wiggle the plug as you pull on it.

    PHOTO: Remove the ignition switch.

    PHOTO: Remove the ignition switch.

  3. 03.

    Install the new ignition switch

    Connect the wire harness to the back of the ignition switch.

    Push the new ignition switch into the dash and engage the locking tabs.

    Lower the hood.

  4. 04.

    Reconnect the battery

    Reconnect the negative cable to the negative battery terminal.

    Lower the seat.

Warning: Undertaking repairs to power lawn-care equipment can be hazardous. Use the proper tools and safety equipment noted in the guide and follow all instructions. Do not proceed until you are confident that you understand all of the steps and are capable of completing the repair. Some repairs should only be performed by a qualified technician.

Symptoms common to all riding mowers & tractors

Choose a symptom to see related riding mower and lawn tractor repairs.

Main causes: punctured tire or inner tube, leaky valve stem, damaged wheel rim
Main causes: worn or broken ground drive belt, bad seat switch, transaxle freewheel control engaged, transaxle failure, dirty carburetor
Main causes: shift lever needs adjustment, neutral control needs adjustment
Main causes: worn or broken blade belt, broken belt idler pulley, blade clutch cable failure, bad PTO switch, damaged mandrel pulleys
Main causes: damaged cutting blade, worn deck pulley, damaged mandrel pulley, loose fasteners on mower deck components
Main causes: engine overfilled with oil, leaky head gasket or sump gasket, damaged carburetor seals, cracked fuel pump, broken fuel line
Main causes: clogged carburetor, damaged flywheel key, dirty spark plug, stale fuel, improper valve lash, engine needs a tune up
Main causes: faulty battery, bad alternator
Main causes: unlevel mower deck, dull or damaged cutting blades, worn mandrel pulleys, bent mower deck, engine needs tune up

Repair guides common to all riding mowers & tractors

These step-by-step repair guides will help you safely fix what’s broken on your riding mower or lawn tractor.

January 1, 2015
By Lyle Weischwill
How to replace a riding lawn mower rear tire

Your mower can’t run on a damaged rear tire. Here’s how to install a new one.

Repair difficulty
Time required
 60 minutes or less
January 1, 2015
By Lyle Weischwill
How to replace a riding lawn mower blade

If a blade on your mower is dull or bent, replace it following the steps in this repair guide.

Repair difficulty
Time required
 30 minutes or less
January 1, 2015
By Lyle Weischwill
How to replace a riding lawn mower fuel filter

Help your mower run better by replacing the fuel filter during your riding mower's annual tune-up.

Repair difficulty
Time required
 15 minutes or less

Articles and videos common to all riding mowers & tractors

Use the advice and tips in these articles and videos to get the most out of your riding mower or lawn tractor.

August 6, 2020

How to remove a lawn mower blade using a removal tool

By Sears PartsDirect staff

Learn how a blade removal tool makes replacing the blade easier and safer

April 9, 2019

Riding mower parts and supplies to stock up on video

By Sears PartsDirect staff

Keep these 6 things on hand to keep the mower season running smoothly.

January 1, 1970

How to tell if a fuse is blown

By Lyle Weischwill

Learn how to tell whether a fuse is blown