How to Wire Ignition Switch & What Wires Go to Ignition Switch

The ignition switch is responsible for turning on the circuits or signals that get the vehicle to start. Replacing the ignition switch becomes imperative when it becomes difficult to turn on the vehicle’s electrical system or say the starter motor does not stop turning even after the motor is on. You never know when it might fail, so you need to understand how to wire ignition switch.

Thankfully, it is not a complicated process to handle once you have the know-how. This article will walk you through the steps needed to wire your vehicle’s ignition switch.

Read on.

How to wire ignition switch step by step

how to wire ignition switch to starter

Here are the steps you need to take to wire the ignition switch yourself. However, depending on the vehicle in question, you might need a push-button starter switch wiring diagram.

Step 1: Park the Vehicle

Ensure that your vehicle is parked on level ground before turning off the engine.

 Step 2: Ascertain the Terminals on the Ignition Switch

Ascertain and locate and ascertain the pins on the back of the vehicle’s ignition switch. Depending on the car, you’d find four terminals that are marked as “BATT”(Battery), “ST” (Start), “IGN”(Ignition), and “ACC”(Accessory).To be on the safe side, get some confirmation from your car’s repair manual or the manufacturer.

Step 3: Disconnect the Battery Terminals

 Disconnect the negative terminal on the battery. There are two terminals marked positive (+) and negative (-) on your vehicle’s battery.  Use a wrench to loosen the bolt before disconnecting the battery terminals. Ensure that you secure the negative cable safely to prevent it from coming in contact with any of the terminals in the course of wiring the ignition.

 Step 3: Remove Steering Wheel Trims

Take away any trim that might be around the steering wheel. You might have to remove them by taking off the plastic clips, securing them, or unfastening any bolts or screws. Once you have taken them off, keep them somewhere safe where they won’t get damaged.

Step 4: Disassemble The Steering Wheel

Remove the steering wheel. Some vehicles have their ignition switch in the dashboard, while others might have it along the steering column. Regardless of its location, removing the steering column will make your job a lot easier. You might need to do this using a steer wheel puller to make your task easier for you. It is important that you consult the repair manual for your vehicle before undergoing this step. Or better still get a racing ignition switch panel wiring diagram

Step 5: Free Up the Ignition Module Cover

Unlock the hooks on the ignition module cover. This allows you to take away the cover so that you can access the ignition switch. There should be some releases on the clips. You might need a screwdriver to be able to press down the release mechanism on the hooks.

Step 6: Keep the Keys in the Right Position

Set the key in the ignition and turn it to the “accessory” position. It is necessary to do this because this is the only way to release it from the ignition module. If you don’t have access to your car key at the moment, you might need to use a flathead screwdriver instead.

If you have to use a flathead screwdriver, then you’d need to be careful. Start by pressing the release pin inside the hole on the ignition module with the screwdriver. There should be a tiny hole to insert the screwdriver and press down on the release pin inside.

Step 7: Release the Pins

Once the release pin that secures the ignition switch is released, you can pull it out from its position. If you got all the steps right up to this point, you should be able to pull it out easily. If, however, you encounter some resistance, ensure that you are pressing the release pin firmly enough.

Step 8: Take a Look at the Ignition Switch

Check the switch to ascertain what is wrong with it. You’d need a test light to do this. Depending on the manufacturer, the dealership involved, and your needs, you might need to rebuild the ignition or get a new one.

Step 9: Check the Wires

Ascertain the positive power lead from the battery to the vehicle’s ignition switch. It is often a thick red wire that is always energized. Once you have identified it, fit the right terminal end on the power lead wire and secure it with a terminal multi-tool. You then connect the power lead to the “BATT” terminal of the switch.

Step 10: Connect the Accessory Wire

Install the accessory lead wire to the “ACC” terminal of the ignition switch. This wire is responsible for energizing the car’s accessories when the ignition switch is turned to the “ACC” position.

Step 11: Connect Starter Relay Wire

Fit the starter relay wire to the “ST” terminal of the ignition switch. The “ST” terminal only starts when the ignition switch is turned to the “START” position.

Step 12: Attach the Ignition Wire

Attach the ignition wire to the “IGN” terminal of the vehicle’s ignition switch. The central terminal serves the car’s ignition, wipers, accessories, and other operating features. It is essentially the default “run” position of the ignition switch.

 Step 13: Reinstall the Ignition Switch

To install the newly rewired switch, you’d need to apply some pressure on the release pin so that you can put the new ignition switch in. Once that is done, you put the new(or rebuilt) ignition switch in the steering column.

You want to line up the shape of the cylinder, the position of the release pin, and the coinciding grooves in the ignition module. You will hear the click of the release pin as the ignition switch sets into place. Don’t stop pushing the ignition switch in until you hear the click from the release pin.

Step 14: Test the Ignition Switch

Once you have secured the ignition switch, it is time to test the newly wired ignition switch. To do this, you’d have to reconnect the battery. There is no need to reassemble any of the components until you are sure that the new ignition switch is appropriately working.

To reconnect the disconnected negative battery terminal, insert the key and try to turn the ignition. If the ignition is in good condition and you have done an excellent job, the car should turn quickly. If it doesn’t, then you might have to repeat the process.

Step 15: Reassemble the Car Parts

Once you have verified that the ignition switch is in good working condition, the next step would be to reassemble the parts. Shut down the engine before disconnecting the battery as you did at the start of the procedure.

You might need to consult your vehicle’s repair manual to get the vehicle’s pieces to fit back correctly again. Whatever you do, ensure that you put the right components in the right place with the screws, bolts, and clips attached as suggested in the car’s repair manual, especially if you have to deal with any of the installed devices in newer car models.

If you follow these steps to this point, you will be able to wire your ignition switch successfully with little or no hassles.

What wires go to the ignition switch

Most cars are set up differently, but depending on the vehicle, you’d find four terminals. These terminals are marked as “BATT”(Battery), “ST” (Start), “IGN”(Ignition), and “ACC”(Accessory).To be on the safe side, get some confirmation from your car’s repair manual or the manufacturer. That way, you avoid making unnecessary errors. Another great idea would be to consult a 4 wire ignition switch diagram.


Q: Where do ignition switch wires go?

The vehicle’s ignition wire goes to the “IGN” terminal of the ignition switch. This is an essential terminal because it serves the vehicle ignition, wipers, accessories, and other operating features. It is also the normal “run” position of the switch.

Q: What color do wires go to the ignition switch?

The colors of the wires that go to the ignition switch are red, black, white-Red, and white black.

Q: Does the ignition switch need to be grounded?

No. Your vehicle’s ignition switch won’t need to be grounded to start your car. This is because all the terminals in the car’s ignition switch should be isolated from the grounds. Once these terminals have been separated from the grounds, the rest of the car’s ignition switch serves mechanical functions.

Q: Can ignition switch cause car not to start?

Yes. It is one of the problems associated with car starting issues. This is because any issues with the ignition switch could be due to electrical problems. Once your car battery is in good condition and your car refuses to turn after a few tries, you might have some issues with the ignition switch.

Q: Can you bypass the ignition switch?

Yes, you might be able to handle it if you have the training and experience. Without any of these things, you might not be able to do it yourself because it is a technical procedure that requires more than a manual and a can-do spirit.

Your best bet would be to get professional help to avoid any complications that might arise.

Final Words:

The ignition switch of vehicles is arguably the most essential part of the car’s electrical system. Like all vehicle components, they fail after repeated use. A failed ignition switch can be inconvenient, which is why you need to know how to wire an ignition switch.

This article has provided a sequence of steps that should help you wire your vehicle’s ignition switch whenever the need arises. All you need to do is to follow them to the letter. We also recommend that you get a universal ignition switch wiring diagram.

Osuagwu Solomon

Osuagwu Solomon is a seasoned automotive technician for the past 9 years, and a technical writer. He loves writing about auto professional repair guides, DIY repair guides, and buyer’s guide. After spending six years in the automotive workshop, he decided to impact his knowledge to people aside his domain, and he has achieved this by centering his Automotive writing skills on REPAIRS.

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