John Deere LA115 Dies When You Release the Brake? Step-by-Step Safety Switch Diagnosis & Fix

Individualized Repair
Jul 31
3 min read

If your John Deere LA115 riding mower dies when you release the brake or clutch, chances are it's a faulty seat switch, brake switch, or PTO switch—but not always the one you expect.

This comprehensive repair guide walks you through how to test every safety switch on your mower, with easy multimeter steps and clear troubleshooting tips. Whether you’re using a John Deere, Cub Cadet, Craftsman, or any other MTD-built riding mower, this guide will help you get it running again. See the full video on Youtube if you would rather watch a walkthrough

What’s the Problem?

A customer brought in a John Deere LA115 riding mower that shut off immediately when releasing the brake. This is a common issue across many mower brands, and while the seat switch is often blamed, it’s not always the root cause. In this repair, we’ll show you how to check each switch and uncover some less obvious electrical issues that could be causing your mower to stall.

Step 1: Test the Seat Switch

The seat switch is the first suspect in most cases. To check it:

Remove or tilt the seat to access the switch
Unplug the connector carefully by prying the tab
Remove the switch by pinching the sides and sliding it out
Use a multimeter in continuity mode (beep or ohm symbol)

What to Look For:

If the switch is labeled NC (normally closed), it should beep (or show continuity) when not pressed
Press the switch—continuity should stop
If it’s intermittent, sticky, or behaves inconsistently—it’s bad

Note: Some seat switches only have two terminals. The same rule applies—if it doesn’t switch properly between open and closed, replace it.

Step 2: Test the Brake, PTO, and Reverse Switches

If the seat switch is fine, move on to the other safety switches.

Brake Switch (Clutch Safety Switch)

Typically located near the brake or clutch pedal
Set multimeter to continuity mode
Should be closed (connected) when pedal is not pressed
Should open (no continuity) when pressed

PTO Switch (Manual or Electric)

Found under the dash or fender depending on model
Has a common terminal and two outputs (normally open + normally closed)
Toggle it and test continuity between terminals
If any connection fails, replace the switch

Reverse Mow Switch

Usually two-prong
Test same as brake switch
These usually don’t cause mower shutdowns, but it’s good to rule out

Step 3: Look for Hidden Electrical Issues

If all the switches test good, there’s one more often-missed culprit:The connector underneath the seat.

Why This Matters:

These connectors are designed to prevent people from bypassing safety switches. If the internal ground-bridge insert fails inside this connector, the mower may shut off even if the seat switch is working perfectly.

The Fix:

Leave the seat switch plugged in
Use a flathead screwdriver to remove the internal bridge insert
This bypasses the failure point without disabling safety features

Bonus Tip: Check the Wiring Harness

If none of the above work, inspect for:

Burnt wires
Melted connectors
Broken leads between switches

In our repair, we ultimately replaced the seat switch and confirmed proper operation. The mower no longer dies when the brake is released.

Conclusion

If your John Deere LA115 stalls when you release the brake, follow this full diagnostic walkthrough before replacing random parts. Safety switches often fail—but so do the connectors and wires that tie everything together. With a multimeter and a few minutes of testing, you can avoid the guesswork and get your mower running again.

Watch the Full Video Repair Guide on YouTube

Frequently Asked Questions (FAQ)

Q: Why does my John Deere riding mower die when I let off the brake?

A: It's usually a failed seat switch, brake/clutch switch, or a bad seat connector that breaks the safety circuit.

Q: Can a PTO switch cause my mower to shut off?

A: Yes, even if your PTO engages, a faulty switch can still kill the engine if it doesn’t signal properly to the ignition system.

Q: What if I replaced the seat switch and it still shuts off?

A: Check the seat switch connector underneath the seat—it often fails internally even if the switch is new.

Q: How do I test mower safety switches?

A: Use a multimeter set to continuity (beep mode) to test open/closed function depending on the switch type (NC or NO).