What Wires Go to the Ignition Switch? | How to Wire an Ignition Switch?

The ignition switch is an electric device that sends signals to the electrical circuits to start a car. It is one of the most critical parts of your vehicle. It becomes mandatory to install a new ignition switch if the starter motor or electrical system of the vehicle doesn’t start. There is a probability that the ignition switch may not sometimes work due to wrong connected wires. Therefore, you need to know how to install and wire the ignition switch and what wires go to the ignition switch.

Substantial knowledge of wiring is required if you want to repair or replace a new ignition switch. This is a hectic task that not only requires a lot of time for execution but also requires mechanical skills and experience.

In this article, you will deeply learn how to connect an ignition switch to a car. You will also learn what wires go to the ignition switch and how to connect them. 

How to Wire an Ignition Switch?

The wiring for an ignition switch depends on the vehicle model. The activity of the wire connection to an ignition switch may vary from vehicle to vehicle.

The latest cars (such as sophisticated or sports cars) may have multiple various wires connected to the ignition switch. However, the older car ignition system has a simple procedure for wiring an ignition switch into an automobile car.

Wires Go to the Ignition Switch diagram

It is better to properly read the wiring circuit diagram of your car to properly understand how to turn your ignition switch and to prevent any damage to electrical parts.

Following are the steps that you can follow to wire an ignition switch into a vehicle.

  • Vehicle Parking
  • Locate the Ignition Switch’s Terminals
  • Unplug the Battery Terminals
  • Remove Steering Wheel Trims
  • Take the Steering Wheel Off
  • Remove the Ignition Module Cover
  • Insert the Ignition key in the right position
  • Release the Pins
  • Inspect the Ignition Switch
  • Identify the Wires
  • Connect the Accessory Wire
  • Connect the Starting Relay wires
  • Attach the Ignition Wire
  • Reinstall the Ignition Switch
  • Test the Ignition Switch
  • Reassemble the Car Parts

1) Vehicle Parking

When you switch off the engine, be certain that your car is parked on a flat floor.

2) Locate the Ignition Switch’s Terminals

The rear of an ignition switch contains the following four terminals:

  • BATT
  • IGN
  • ST
  • ACC

Find and identify these terminals. These terminals may be labeled with slightly different letters or numbers depending on the model, design, and ignition switch manufacturer of your vehicle. To easily identify these terminals, it is always recommended to reference the manufacturer of the ignition switch and your car’s service manual.

ignition switch wiring diagram

If you are unsure about the labels on the terminals, check the vehicle’s ignition switch wiring schematic if needed. 

3) Unplug the Battery Terminals

It’s preferable to unplug the battery terminals before performing any work on the vehicle. The positive terminal and negative terminal of the battery are apparent when you lift the hood of your car. Disconnect the negative (-) terminal of your battery by loosening the bolts. Use a small socket and ratchet for this process.  

4) Remove Steering Wheel Trims

Remove any trim that may be surrounding the steering wheel right away. The trim may be held in place by plastic clips. During reassembly, be careful to put any screws, clips, or nuts in a secure position.

In many situations, removing the steering wheel also simplifies the process. To simplify things, you may use a steering wheel puller.

Read More: How to Unlock Steering Wheel without a Key?

5) Take the Steering Wheel Off

In some car models, the ignition switch is installed along with the steering column, while others may have it in the dashboard. No matter where it is, removing the steering column will greatly simplify your task.

To make the process easier for yourself, you may use a steer wheel puller. Before carrying out this procedure, it is recommended that you should examine the vehicle’s repair manual. It is even better if you can get a racing ignition switch panel wiring diagram.

6) Remove the Ignition Module Cover

The ignition module cover’s hooks should be unlocked to access the ignition switch easily. This step will help you to remove the cover so that you can reach the ignition switch easily. On the clips, there need to be some releases. The release mechanism on the hook may require to be pressed down with the use of a screwdriver.

7) Insert Ignition key in the right position

Rotate the ignition key of your car to the ACC (accessory) position after inserting it into the ignition switch. This step is necessary for pressing the release pin and taking the ignition switch out of the module.

Use a flathead screwdriver to do this task if you don’t have your car’s ignition key, but be cautious not to harm the ignition barrel slot.

Read More: Why is Ignition Key Stuck in Ignition Switch?

8) Release the Pins

You can easily remove the ignition switch from its location when the release pin that holds it in its place has been loosened. It should be simple to remove the ignition switch if you followed the directions exactly up until this point. But if there is resistance, make sure you are pushing the release pin hard enough.

9) Inspect the Ignition Switch

Properly inspect the ignition switch after removing it. Your current ignition switch will need to be rebuilt if you wish to continue using the same keys. If not, you may buy and install a new ignition switch according to your vehicle’s specifications. 

10) Identify the Wires

Find the positive (+) power lead that links the ignition switch to the battery in your car. Typically, this wire has a thick red color.

After locating the positive power wire, attach it to the ignition switch’s BATT terminal by using a terminal multi-tool.

Read More: Bad Ignition Switch Symptoms and Causes

11) Connect the Accessory Wire

Now, it’s time to connect the accessory lead wire. Attach the accessory lead wire to the ignition switch’s terminal labeled as ACC. When you turn your ignition key in the ACC position, this wire regulates the accessories of your car.  

12) Connect the Starting Relay Wires

Attach the starter relay wire to the ignition switch’s ST terminal. This wire should be connected to the ST terminal of your ignition switch.

When you turn the ignition key in the “START” position, this wire immediately makes a connection to the starter solenoid of your car and turns on the starter motor.

13) Attach the Ignition Wire

The ignition wire should be connected to the ignition switch’s IGN terminal. The IGN terminal represents the “run” state of your car which regulates the ignition and other electrical activities of your car. 

14) Reinstall the Ignition Switch

Reinstall the rebuilt or new ignition switch back in its original place by aligning the cylinder. Sometimes it’s necessary to push down the release pins slightly. Once you hear the release pin click, you will know the switch is properly positioned in the engine cylinder

15) Test the Ignition Switch

Test your freshly connected ignition switch after securing it properly. You would need to reconnect the battery to test the switch. You don’t need to put any of the parts back together until you are certain that the new ignition switch is working according to requirements.

Insert the ignition key in the switch and attempt to turn the ignition to reconnect the disconnected negative battery terminal. Your vehicle engine should start immediately if the ignition is installed properly. You might need to redo the process if your engine doesn’t start.

16) Reassemble the Car Parts

You are ready to drive your car if everything is operating properly. Start by shutting off the engine and reconnecting the battery.

After that, install the vehicle parts back together precisely in their original locations. Consult your repair manual or try searching online for the location of a part if you can’t recall where it goes. 

What Wires go to the Ignition Switch

The wires connected to an ignition switch are highly dependent on the vehicle model. However, depending on the vehicle model, you will find four terminals that are mentioned below:

  • ACC (accessory). The main function of the ACC terminal is to send electricity to the electrical parts of your car, such as the windshield wipers, radio, and lights. This terminal usually contains a purple.
  • BATT (battery). The BATT terminal usually has a thick red wire. It is always energized generally connects here.
  • ST (starter). It is connected to the starter solenoid. ST terminal contains a yellow or brown.
  • IGN (ignition input). The IGN terminal of your vehicle’s ignition switch is used to control the ignition of the vehicle and other electronics. It is considered a primary terminal. It usually has red or yellow.

Check the manufacturer’s manual to ensure the color coding for each ignition switch terminal. With this method, you may prevent mistakes in this process. A 4-wire ignition switch schematic would be a fantastic additional suggestion. The 4 pole ignition switch wiring diagram is given below:

4 wire ignition switch diagram
4 Pole Ignition Switch Wiring Diagram

FAQ Section

What is the function of the ignition switch?

It is one of the most important components of the vehicle. The electrical and ignition systems in your vehicle rely heavily on the ignition switch.

The main function of the ignition switch is to produce the energy needed to ignite the gasoline in the engine, which produces energy between 20 and 30 thousand volts. The ignition switch of your vehicle takes power from the 12-volt battery of the vehicle and supplies this power to the starting solenoid and other electrical accessories. 

How many wires does an ignition switch have?

A simple ignition switch typically contains the following four wires:

  • Starter (ST) wire
  • Ignition (IGN) wire
  • Accessories (ACC) wire
  • Battery (BATT) wire

The latest vehicle models may have more than four wires going to the ignition switch.

Where do ignition switch wires go?

The “IGN” terminal of the ignition switch is connected to the vehicle’s ignition wire because it controls the accessories, wipers, ignition, and some other important functions of your car. That is also the standard “run” position of the switch.

What color do wires go to the ignition switch?

The ignition switch type and the vehicle model determine the wiring colors that go to the switch. The battery wire usually contains blue color, the starter cable is green, the accessory cable is red, and the ignition cable is usually yellow.

You should check your vehicle manual first before drawing any conclusions about the wiring colors.

Does the ignition switch need to be grounded?

No, the ignition switch doesn’t need to be grounded. You can start your car without grounding the ignition switch. This is due to the fact that all the ignition switch’s terminals are separated from one another and the ground. Once these terminals have been disconnected from the grounds, the ignition switch’s remaining components perform mechanical tasks.

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