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 replacement 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.

    Disconnect the battery.

    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.

    Remove the ignition switch.

    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: worn or broken ground drive belt, bad seat switch, transaxle freewheel control engaged, transaxle failure, dirty carburetor
Main causes: dead battery, stale fuel, bad starter solenoid, ignition system problem, bad ignition interlock switch, clogged carburetor
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: punctured tire or inner tube, leaky valve stem, damaged wheel rim
Main causes: unlevel mower deck, dull or damaged cutting blades, worn mandrel pulleys, bent mower deck, engine needs tune up
Main causes: damaged tie rods, bent or worn wheel spindle, worn front axle, damaged sector gear assembly
Main causes: worn or broken blade belt, broken belt idler pulley, blade clutch cable failure, bad PTO switch, damaged mandrel pulleys
Main causes: shift lever needs adjustment, neutral control needs adjustment

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.

How to replace the starter motor on a riding lawn mower

If you hear the solenoid click but don’t hear the starter motor spin when you turn the key, follow these steps to replace it.

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

If the engine is hard to start or if the spark plug electrode is burnt or cracked, take 15 minutes to replace it.

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

If the engine of your lawn tractor surges or is hard to start, the carburetor could be the problem. Follow these steps to install a new one.

Repair difficulty
Time required
 45 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.

May 1, 2017

Riding lawn mower engine spins but won't start video

By Sears PartsDirect staff

Troubleshoot fuel, spark and compression issues.

June 1, 2016

How to mow a lawn for healthier grass

By Erin Hynes

How often and tall you mow your lawn has a big impact on its health. Check out these 3 rules.

March 1, 2016

How to change the Smart Switch Ignition password on a lawn tractor video

By Sears PartsDirect staff

See how to unlock the factory default start code so you can set your own passcode.