Everything to know about ignition relay

There are a few steps you must take before you may get in the car and turn on the motor. One of the most important—and frequently disregarded—parts of any car ignition system is the ignition relay. A small electrical component called the ignition relay is situated in a large current motor’s starting circuit. A high-current circuit’s current is controlled by the relay, which is merely a remote-control switch. The car’s ignition relay closes the much more potent starting circuit with a modest amount of ignition switch electricity.

In numerous automotive applications, the ignition relay and the starter solenoid team up to power the starter mechanism. In some situations, an ignition switch can directly control a starter solenoid circuit. Since these are often little cars, the starter motor doesn’t need a lot of electricity to operate. Well in this article we’ll be discussing the necessary things to know about ignition relays.

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  • What is an ignition relay?
  • Where is the Ignition Relay Located?
  • What are the Symptoms of a Bad/ failing Ignition Relay?
  • How do you test an ignition relay?
  • What are the functions of an ignition relay?
  • How much is a relay Replacement Cost?

So, let’s begin!


What is an ignition relay?

The ignition relay is essentially a piece of electrical equipment that switches power to your car’s fuel system and ignition system. As soon as you turn the key in the ignition of your car, the ignition relay is put into action.

The ignition relay then turns on the power and permits it to reach the systems that must be powered on in order for your vehicle to operate. As a result, the battery sends energy to the ignition coil, which in turn sends energy to the spark plugs in your car to start the engine.

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Where is the Ignition Relay Located?

Depending on the car’s design and manufacturer, the precise location of the ignition relay may vary from one vehicle to the next. The fuse box under the hood is frequently where you’ll find the ignition relay. It can also be found within the car, in a fuse box under the dashboard.

You can use the repair handbook that the manufacturer of your car gave you to locate the ignition relay quickly and identify it correctly. Along with many other relays mounted on it, it will be found in the relay panel.

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What are the Symptoms of a Bad/failing Ignition Relay?

Below are the symptoms of a failing ignition relay;

  • Car Ignition problem
  • Engine Stalls
  • Dead Battery after night
  • Fluctuating Ignition power
  • Bad electronic smell

Car Ignition problem

  • Giving power to all of your car’s control modules and sensors that are required for the engine to run is the ignition relay’s main duty, when it fails to deliver any of these then be certain that your ignition relay has a problem
  • There is a significant chance that the ignition relay is malfunctioning if nothing happens on your dashboard when you turn the key in the ignition lock and you are certain that the car battery is charged. These problems must be resolved right away. You’ll have to travel without your car if you don’t.

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Engine Stalls

  • Power for crucial engine components like the fuel pump and ignition coils is provided by the ignition relay. You may probably predict what will happen if it can’t supply electricity to them because, without these parts, your engine will quickly shut down.

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Dead Battery after night

  • In order to prevent the battery from being drained while you leave the car standing overnight, the ignition relay should also turn off power to all engine components when the ignition key is turned off.
  • When the ignition relay malfunctions, the ignition system may continue to operate even after the keys have been withdrawn from the ignition.
  • This implies that the circuit won’t operate after the key is removed, and the battery will discharge.
  • In light of this, the ignition relay may have been to blame for a battery that failed while operating flawlessly the day before.

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Fluctuating Ignition power

  • There might be a problem with the ignition relay if your dashboard is blinking like a game of table-flipping.
  • When corrosion develops inside the ignition relay, problems can arise. As a result, the connecting space inside the relay may get too narrow, which would result in the ignition turning off and on very quickly.

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Bad electronic smell

  • Heat is produced by a poor electrical connection. A poor connection can form inside an ignition relay if it has corrosion, rust, or water, which can generate a lot of heat.
  • Frequently, you may see that the plastic relay cover has melted. If you’ve ever smelled burnt electronics, you should definitely check the ignition relay the next time you get that sensation.

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How do you test an ignition relay?

Below are the materials and tools needed for a successful test;

  • Fully charged battery
  • Baking soda, water, and wire brush
  • A portable jumper cable manufacturing technology
  • Safety glasses and gloves

Below are the steps involved in testing an ignition relay;

  • Make sure the transmission is in neutral or the “parked” position and that the car is parked securely. You don’t want the car to move forward unintentionally while you’re working below it.
  • A fully charged battery and a portable jumper should be ready before testing. Alternatively, you may make sure your car battery is fully charged and isn’t the problem by checking it. Please pay close attention to how the jumper cable is connected to the battery terminal throughout the entire test.
  • Examine the battery and ignition connection terminals. Make sure there is no dust, grease, rust, or debris on them. Remove the negative battery cable and place it aside before cleaning corroded terminals. The battery-positive cable should be unplugged from the battery and laid aside. Make sure the cables don’t unintentionally come into contact with the battery connections. The rusted terminals can be cleaned using baking soda, water, and a wire brush. Clean the starter terminal if necessary. Disconnect the battery cable if you can.
  • It is important to follow the cable that runs from the ignition solenoid to the starting relay. On the relay, there are four terminals. Two smaller wires from the crucial switching circuit are utilized to “turn on” the relay. The battery voltage is sent from the battery to the starter by two bigger cables. Mark the two smaller wires before removing the wires from the ignition relay so that they may be re-joined properly. Jumper wires are connected with one end to the chassis ground. The other end needs to be attached to Terminal 86.
  • Attach a jumper wire to the battery’s positive terminal. The jumper can be connected for a brief period of time because the battery and ignition connection has been severed. The resistance between terminals 30 and 87 must be measured with a digital voltmeter. Its resistance needs to be under 1 ohm. The relay is inoperative if the resistance is higher than 1 ohm. It’s necessary to swap out the relay.

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What are the functions of an ignition relay?

  • The ignition relay serves as a circuit completer or circuit breaker between the vehicle’s battery and the starter motor. By increasing the battery’s current, less current must be ignited, which is beneficial. This is a switch between the start solenoid and the starter motor, per the description.
  • A sizable current is produced when you turn the ignition key or depress the car’s start button. The ignition switch cannot be adjusted, and the starter motor consumes a significant amount of current. The relay will burn out if there isn’t one.
  • The vehicle might not start if the ignition relay malfunctions. There are numerous possible causes for this component to malfunction, as we will discover later. Depending on the type and degree of the risk, they also need a variety of therapies. Some can be fixed, while others need new relays to be installed.

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How much is an ignition relay Replacement Cost?

Depending on the car’s model and labor expenses, replacing an ignition relay typically costs between $15 and $100. Costs for labor and ignition relays range from $10 to $50.

Depending on whether you want to purchase an OEM or aftermarket ignition relay, you might anticipate paying less than $10 for the relay itself.

The replacement of the ignition relay is frequently also fairly simple. If you prefer a mechanic to handle it instead, you may anticipate paying between $15 and $100 for the replacement.

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Ignition relay FAQs

What causes a relay to fail?

Springs gradually lose their resilience. Poor contact alignment and open coils can also cause relays to malfunction. The key element influencing relay reliability is choosing the right relay type for a particular application. When incorporating them into circuits, numerous subpar design techniques are employed.

Can a bad relay drain your battery?

The ignition relay is essentially a switch for the power to the ignition system’s electrical components. Its responsibility is to ensure that electricity is transferred from the battery to the various devices that require it. Your battery will be depleted and the ignition will be challenging to start due to a bad relay.

What is the function of a relay in a car?

What functions does a relay serve in a car? Relays are widely used in circuits to reduce the amount of electricity flowing through the primary control switch. To turn on and off a much better potential relay, use a sensor, timer, or switch with a very low amperage.

How many relays are in a car?

Up to twenty automotive relays can be found in a standard car, and they can be found all over the place.

How do you reset a relay switch?

Use a push button as a start and a relay contact (or an aux relay) as a hold-in across the start button to make things simple. At that point, your float switch is a series stop switch. Naturally, the latter would need to be shut down during regular business hours.

What happens if the ignition relay fails?

The fuel pump and ignition system will lose power if the relay malfunctions, which will cause no power and, consequently, no start. The accessories and maybe the engine can be turned on by turning the key.

How long do ignition relays last?

every time the car is started, the ignition relay is activated. The ignition relay is made to survive as long as the car, much like the other relays on it.

What is the purpose of a fuse in the ignition system?

Fuses serve as safety valve that limits the amount of electricity that can pass through wiring and other electrical circuit components. Short circuits or overcurrent occurrences can result in overloads. If the fuse’s current rating is exceeded, the metallic “element” of the fuse overheats, melts and opens the circuit.

That’s all for this article where we discussed the answers to the following questions related to ignition relay;

  • What is an ignition relay?
  • Where is the Ignition Relay Located?
  • What are the Symptoms of a Bad/ failing Ignition Relay?
  • How do you test an ignition relay?
  • What are the functions of an ignition relay?
  • How much is a relay Replacement Cost?

I hope it was helpful, if so, kindly share. Thanks for reading.