The roar of a lawnmower is a familiar sound of summer, but what happens when that roar turns into a frustrating silence? A faulty relay is a common culprit behind lawnmower starting problems, leaving you staring at your neglected lawn with a sense of dread. But fear not! This comprehensive guide will equip you with the knowledge to test your lawn mower relay and get back to mowing in no time. We’ll cover what a relay does, how to identify a faulty one, and walk you through the testing process with clear instructions. So, grab your tools and let’s get started!
What is a Relay, and Why Does it Matter?
A relay acts as a switch, controlling the flow of electricity to your lawnmower’s starter motor. When you turn the key, the relay receives a signal, which in turn closes the circuit and sends power to the starter. This allows your engine to crank and start. A faulty relay, however, can disrupt this process, preventing your mower from starting. It’s essentially a mini-circuit breaker, preventing damage to your starter by protecting it from excessive current.
Recognizing the Symptoms of a Faulty Relay
Before you dive into the testing process, it’s crucial to identify if your relay is indeed the problem. Here are some common signs:
- The starter motor doesn’t engage: This is the most obvious symptom. You turn the key, hear a clicking sound, but the engine doesn’t even attempt to crank.
- You hear a clicking sound when turning the key: This suggests the relay is receiving power but failing to complete the circuit to the starter.
- Intermittent starting problems: Sometimes your mower starts, but other times it doesn’t, suggesting a faulty relay that’s intermittently functioning.
Testing Your Lawn Mower Relay: A Step-by-Step Guide
Safety First: Always disconnect the battery before working on any electrical components in your mower.
Tools Needed:
* Multimeter: A basic multimeter with both voltage and continuity testing capabilities is essential for this task.
* Screwdriver: A Phillips head screwdriver is usually required to access the relay.
* Wire connectors: These are helpful for temporarily connecting test leads during testing.
1. Locate the Relay
The relay is usually a small, black box with multiple wires connected to it. It’s often located near the starter motor, battery, or fuse box. Check your owner’s manual or search online for your specific model to pinpoint its location.
2. Disconnect the Relay
Once you’ve located the relay, disconnect the wires connected to it. Use wire connectors to keep the wires organized.
3. Visual Inspection
Before starting any electrical tests, give the relay a visual inspection. Look for:
* Burned or melted wires: This indicates potential overheating and damage.
* Loose or corroded connections: Clean any corrosion with a wire brush.
* Damaged or cracked housing: A damaged housing could indicate internal issues.
4. Resistance Test
- Set your multimeter to the “ohms” setting.
- Connect the probes to the appropriate terminals on the relay. The relay will have a few terminals; consult your owner’s manual or the relay diagram for the correct terminals to connect. Usually, terminals 85 and 86 are used for the coil, and 30 and 87 for the contact points.
- Check for continuity: You should read a low resistance value (usually under 10 ohms) when the probes are connected to the coil terminals.
- Check for open circuit: If you get a reading of “OL” (open loop), or a very high resistance, the coil is faulty.
5. Voltage Test
- Set your multimeter to the “volts DC” setting.
- Connect the red probe to the positive (+) battery terminal and the black probe to the negative (-) battery terminal.
- Turn the ignition key to the “start” position.
- Check the voltage reading on the relay terminals: You should see a voltage reading across the coil terminals (85 and 86) and between the contact terminals (30 and 87).
- No voltage readings: If you don’t see any voltage readings, the relay is likely not receiving power, and the issue could lie in your wiring or ignition switch.
6. Relay Functionality Test
This test checks if the relay is functioning properly.
- Connect one of the probes to terminal 30 (or 87) of the relay.
- Use the other probe to touch terminal 85 (or 86).
- Turn the ignition key to the “start” position.
- If the relay is working correctly, you’ll hear a clicking sound and see a voltage change on the multimeter. This signifies the relay is closing the circuit.
7. Replace the Relay
If any of the tests reveal a faulty relay, it’s time to replace it. You can purchase a new relay from your local lawnmower dealer or online. Ensure you get a relay that’s compatible with your mower model.
Other Potential Causes for Starting Issues
While a faulty relay is a common culprit, it’s important to note that other problems can cause your lawnmower to fail to start. These include:
- Dead battery: A dead battery won’t have enough power to engage the starter.
- Faulty starter motor: A damaged starter motor might not be able to turn the engine.
- Fuel issues: A clogged fuel filter, empty fuel tank, or bad fuel can prevent the engine from starting.
- Spark plug problems: A fouled spark plug or a weak spark can cause ignition issues.
- Loose or corroded connections: Inspect all electrical connections for any signs of wear and tear.
Troubleshooting Tip: If your lawnmower has a safety switch, make sure it’s engaged before starting.
Tips for Maintaining Your Lawn Mower Relay
Preventative maintenance can prolong the life of your lawnmower relay:
- Regularly clean and inspect the relay: Dirt and debris can accumulate and cause issues.
- Keep your battery charged: A well-charged battery will ensure enough power for the relay.
- Avoid extreme temperatures: Heat and cold can damage the relay.
Conclusion
Testing your lawnmower relay is a relatively straightforward process that can save you money and frustration. By following the steps outlined above, you can quickly determine if your relay is the problem and take the necessary action to get your mower running smoothly again. Remember to always prioritize safety and use caution when working with electrical components. With a little patience and this guide, you’ll be back to enjoying a beautifully manicured lawn in no time!
FAQs
Q1: What is a relay and why is it important for my lawn mower?
A: A relay is essentially an electrical switch that allows a small electrical signal to control a larger current. In your lawn mower, the relay is responsible for switching the starter motor on and off. When you turn the key, the ignition switch sends a small signal to the relay, which then closes the circuit and allows the battery’s power to flow to the starter motor, turning it on. This relay is crucial because it protects the ignition switch from handling the high current needed to start the motor, which could otherwise damage the switch.
Q2: What are the common signs of a faulty relay?
A: A faulty relay can manifest in several ways. The most obvious symptom is when your lawn mower fails to start, even though the battery is charged and the ignition switch is working. You might hear a clicking sound coming from the relay, indicating that it’s attempting to engage but failing. Other signs include a sluggish starting motor or the engine starting but immediately dying. If you suspect a faulty relay, it’s always best to check it, as other issues could also be the culprit.
Q3: How do I test the relay?
A: Testing the relay is a straightforward process that requires a multimeter. First, disconnect the battery to avoid electrical shocks. Then, locate the relay on the mower, typically near the battery. Use the multimeter to measure the resistance between the relay’s terminals. A faulty relay will show an open circuit or an extremely high resistance. If the relay is working, you’ll get a reading within a specific range depending on the relay’s specifications.
Q4: What should I do if the relay is faulty?
A: If you’ve confirmed the relay is faulty, you need to replace it. Replacing a relay is usually a simple procedure. First, disconnect the battery. Next, locate the relay and disconnect the wires connected to it. Then, remove the faulty relay and install the new one, ensuring the wires are connected correctly. Finally, reconnect the battery and try starting the mower.
Q5: Where can I find a replacement relay?
A: Replacement relays for lawn mowers can be found at most auto parts stores, hardware stores, or online retailers. You’ll need to know the make and model of your lawn mower to find the correct relay. If you’re unsure, consult your owner’s manual or contact the manufacturer.
Q6: Can I use a universal relay?
A: While universal relays exist, it’s not always advisable to use them for lawn mowers. Universal relays may not have the same specifications as the original relay, such as voltage and current handling capacity. Using an unsuitable relay can potentially damage your lawn mower or even cause safety hazards.
Q7: Are there any other potential problems that could cause starting issues?
A: While a faulty relay is a common culprit, other factors can also cause starting problems in your lawn mower. These include a dead battery, a faulty ignition switch, problems with the starter motor itself, clogged fuel lines, or even a faulty spark plug. If the relay is working correctly, it’s essential to rule out these other possibilities before reaching a definitive conclusion.