How to Bypass a Honda Main Relay: A Step-by-Step Guide.


To bypass a honda main relay, locate it and use jumper wires to connect the appropriate terminals. This process is straightforward and requires basic knowledge of electrical connections.

The honda main relay controls the fuel pump and other electrical components. If it fails, the car won’t start or may stall suddenly. Sometimes, the issue lies with the relay itself, and a quick fix is all that’s needed. By bypassing the main relay, you can test if it’s faulty and needs replacement.

The process involves locating the relay, which is usually under the dashboard, and connecting the appropriate terminals using jumper wires. It’s essential to follow the safety precautions and use the correct wire gauge to prevent electrical faults and damage to the car’s computer. With proper guidance, even a novice can perform this task and save on costly repairs.

What Is A Honda Main Relay And What Are Its Functions?

Explanation Of What The Honda Main Relay Is And How It Works

The honda main relay is a crucial component of the fuel, ignition, and starting system of a honda vehicle. It acts as a switch that controls power supply to the engine’s electrical components. A faulty main relay can cause problems such as engine misfire, stalling, or failure to start, as it may not supply adequate power to the vehicle’s components.

The relay is located under the driver’s dashboard, and is connected to the rest of the electrical system through a wiring harness.

When you put the key in the ignition and turn it on, the main relay receives a signal from the pcm/ecu (powertrain control module/engine control unit). The relay then activates, allowing electrical current to flow from the battery to the fuel injectors, ignition coils, fuel pump, and starter.

This starts the engine and allows it to run smoothly.

Overview Of The Functions That The Honda Main Relay Controls

The honda main relay controls several functions that are crucial to the engine’s performance and overall operation. These functions include:

  • Fuel injectors: The main relay activates and sends electrical current to the fuel injectors, allowing them to spray the fuel into the engine’s cylinders. Without the main relay, the injectors would not receive power and the engine would not start.
  • Ignition coils: The main relay also sends power to the ignition coils, which are responsible for creating the electric spark that ignites the fuel in the engine’s cylinders. Without the main relay, the coils would not receive power, and the engine would not start.
  • Fuel pump: The main relay activates the fuel pump that supplies fuel to the engine. Without adequate fuel pressure, the engine could stall or not start at all.
  • Starter: The main relay also sends power to the starter, which is responsible for turning over the engine and starting it. Without power from the main relay, the starter would not be able to turn the engine over.

The honda main relay is a vital component of your honda’s engine system that controls the functioning of the fuel injectors, ignition coils, fuel pump, and starter. Understanding its functions and how it works can help you identify potential issues and seek help from a professional to get your vehicle performing at its best.

Signs And Symptoms Of A Faulty Main Relay In A Honda

The honda main relay is responsible for controlling the electrical supply to the vehicle’s fuel and ignition systems. As a result, when this component starts to fail, it can have a detrimental effect on your vehicle’s performance. Here are some signs and symptoms that indicate a faulty main relay in a honda:

Common Signs That Indicate The Honda Main Relay Is Faulty:

  • Engine won’t start or stalls: The first and foremost symptom of a bad main relay is the engine not starting or stalling during operation. The fuel pump and spark plugs rely on the main relay to work correctly, so when it fails, so do those components.
  • Intermittent working of the engine: If the engine runs fine but starts failing on certain occasions, particularly during hot temperature days, then there are chances of a failing honda main relay.
  • Electrical issues in the vehicle: When the relay starts to malfunction, it can lead to electrical issues in the vehicle, such as the dashboard lights failing to turn on or flickering at low speed.

Specific Symptoms To Look Out For In A Honda Vehicle:

  • Not hearing the fuel pump turn on: When turning the key in the ignition, you should hear the fuel pump turn on. If there is no sound, it could mean that the main relay is faulty.
  • Unresponsive starter: When the relay sends a signal to the starter, it should turn over the engine. If the starter is unresponsive, it could mean that the main relay is failing.
  • Engine sputters: If the engine sputters or backfires while accelerating, this could be due to a poor electrical supply caused by a failing main relay.

The main relay in a honda plays a crucial role in powering the fuel and ignition systems of your vehicle. Therefore, it is vital to be aware of the signs and symptoms of a failing main relay, to avoid engine failure and to keep your honda running smoothly at all times.

Tools And Materials Needed For Bypassing A Honda Main Relay

Bypassing a honda main relay can be tricky if you don’t have the right tools and materials. However, with proper preparation and knowledge, this task can be accomplished with ease. In this guide, we’ll discuss the list of tools and materials needed to complete this process and where to find them.

A Detailed List Of Tools And Materials Needed To Successfully Bypass A Honda Main Relay

To successfully bypass a honda main relay, you’ll need the following tools and materials:

  • Multimeter
  • Wire strippers
  • Electrical tape
  • Soldering iron
  • Solder
  • Heat shrink tubing
  • Electrical wire

Where To Find The Necessary Tools And Materials

You can find most of the tools and materials needed to bypass a honda main relay in automotive stores, hardware stores, and online marketplaces. Here are some examples of where you can purchase these items:

  • Multimeter: You can purchase a multimeter from any electronic store or online marketplace such as amazon, best buy, or walmart.
  • Wire strippers: Hardware stores like home depot, lowe’s, and ace hardware usually have a wide range of wire strippers for you to choose from.
  • Electrical tape: You can purchase electrical tape from any automotive or hardware store, as well as online marketplaces like amazon and ebay.
  • Soldering iron and solder: You can buy a soldering iron and solder from any electronic store or online marketplaces such as amazon or ebay.
  • Heat shrink tubing: You can purchase heat shrink tubing from any hardware store or online marketplaces such as amazon, home depot, and lowe’s.
  • Electrical wire: You can purchase electrical wire from any electronics store, automotive store, or online marketplaces such as amazon or ebay.

Overall, having the proper tools and materials on hand is essential for successfully bypassing a honda main relay. With this guide, you should now have a clear understanding of what tools and materials you need to successfully bypass a honda main relay and where to find them.

Step-By-Step Guide On How To Bypass A Honda Main Relay

Detailed Instructions For Bypassing A Honda Main Relay

Bypassing a honda main relay can be an easy task if you know what you’re doing. Here is a step-by-step guide that will assist you in bypassing a honda main relay easily.

Step 1: Identify The Main Relay

The honda main relay is typically located beneath the dashboard on the driver’s side, near the fuse box. It’s a small plastic box with a plug that contains several wires. Before beginning this task, disconnect the battery and give the engine enough time to cool down.

Step 2: Remove The Relay

Remove the main relay from the mount and set it aside. It should be labeled with numbers that correspond to its pins.

Step 3: Inspect The Relay

Once you have removed the relay, inspect it for any damages or cracks. Use a tester to check its functionality. Most of the time, a faulty main relay may cause starting problems. If the relay seems damaged, you can replace it.

Step 4: Bypass The Main Relay

If you are confident that your relay is faulty, you can bypass it. Locate pins 5 and 7 on the relay plug. Cut a wire connecting these two pins. Strip off the ends of the wire, and connect them with a crimp connector or a wire nut.

Ensure that the joint is secure.

Step 5: Reinstall The Main Relay

Reinstall the main relay in its designated place. Connect the battery back. Turn on the car and verify that it starts correctly. If it does, you have successfully bypassed the main relay.

By following these steps, you should now be able to bypass your honda main relay without much difficulty. Remember to always be cautious when working with electrical components and disconnect the battery before beginning. Good luck!

Safety Precautions For Bypassing A Honda Main Relay

Bypassing a honda main relay is a crucial process for any honda owner to diagnose and fix a non-starting condition. However, it is not only essential to know how to do it, but it’s also crucial to take safety precautions when working on honda vehicles.

Highlighting The Importance Of Safety Precautions When Working On A Honda Vehicle

Honda vehicles are sophisticated machines with complex electrical systems. Even the slightest mistake can lead to severe accidents or health hazards. Therefore, it is essential to follow safety precautions when bypassing a honda main relay. Below are some of the possible risks and hazards that you should be aware of:

  • Sudden electrical shock
  • Fire hazard
  • Explosions due to gasoline or fuel leaks
  • Frisks of falling objects
  • Inhaling toxic fumes
  • Inhaling harmful dust particles

Recommended Steps That Should Be Taken To Avoid Accidents Or Health Hazards During The Bypassing Process

Before proceeding with the honda main relay bypassing process, there are some crucial steps that you should follow to reduce the risks of accidents or health hazards. These include:

  • Disconnect the battery: Before you start working on your honda vehicle, it’s essential to disconnect the battery. Doing this will help you avoid any electrical shock.
  • Work in a well-ventilated area: Always ensure that you work in a well-ventilated area to avoid inhaling toxic fumes or dust particles.
  • Wear protective gear: To avoid any risks of falling objects or inhaling harmful fumes or dust particles, you should wear protective gear such as safety glasses, gloves, and respiratory masks.
  • Keep inflammable substances away: When working on your honda vehicle, always make sure to keep all inflammable substances such as gasoline, fuel, or oil away from the area to avoid any risk of fire or explosion.
  • Follow the manufacturer’s recommendations: Always follow the manufacturer’s recommendations when working on your honda vehicle. Ensure that you use the correct tools and equipment and follow the correct procedures.
  • Don’t rush: Take your time when working on your honda vehicle. Avoid rushing as it can lead to accidents or mistakes.

Bypassing a honda main relay can be daunting, but by following the above safety precautions, you can help prevent any possible accidents or health hazards. As a responsible honda owner, your safety and that of others should always come first when working on any vehicle.

Frequently Asked Questions For How To Bypass A Honda Main Relay

How Do I Bypass A Honda Main Relay?

To bypass a honda main relay, first, remove the fuel pump relay and insert a jumper wire into the two sockets. Turn on the ignition and listen out for the fuel pump sound.

What Causes A Honda Main Relay To Fail?

A failed honda main relay is often caused by high temperatures within the cabin. Over time, the solder holding the connections degrade, causing an intermittent or total failure of the part.

Can I Drive My Car With A Faulty Main Relay?

Driving a car with a faulty main relay is not recommended; the vehicle becomes unreliable and can stall. The issue can escalate, culminating in a complete, abrupt stop. It is best to fix the honda main relay as soon as possible.

How Do I Test A Honda Main Relay?

To test the honda main relay, you need a 12-volt battery, a voltmeter and a jumper wire. Connect the jumper wire to the power and fuel pump socket of the main relay. Turn on the ignition, if there is a voltage reading, the honda main relay is functioning.

Why Is My Honda Not Starting After Bypassing The Main Relay?

If your honda does not start after bypassing the main relay, there could be a problem with the fuel pump or the fuel delivery system. Ensure that the fuel pump is working correctly, and there is sufficient fuel pressure before proceeding.


By learning how to bypass a honda main relay, you can troubleshoot and fix your own car’s starting issues without incurring expensive repair bills. However, it’s important to only perform this procedure if you’re confident in your abilities and understand the risks involved.

Remember to always follow safety precautions such as wearing proper protective gear, disconnecting the battery, and working in a well-ventilated area. Additionally, it’s crucial to use reliable resources and double-check your work to ensure that you’ve properly bypassed the relay and that everything is functioning correctly.

With these tips and a little bit of knowledge, you can tackle your honda’s starting issues with confidence and ease. Happy troubleshooting!

Latest articles


Related articles

Leave a reply

Please enter your comment!
Please enter your name here