How to Wire Ignition Switch and 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 when it fails to signal the starter motor to stop turning once the engine starts running. You never know when it might fail, so you need to understand how to wire the 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. But first, let’s see the wires that go to the ignition switch.

What Wires Go to Ignition Switch

What wires go to the ignition switch

New modern vehicles usually have four wires in the ignition switch. So, if you have a new modern ride, you have four wires in the ignition switch, labeled;

BATT (Battery). The BATT is the terminal to which a thick wire with a red coating connects to. It always has electric flow.

IGN (Ignition Input). This terminal controls and distributes power to the ignition and other car electronic components. It’s usually connected with a red or yellow wire, depending on your car model.

ST (Starter). The ST terminal sends electric flow to the starter solenoid. It usually has yellow or brown coated wire, depending on your car.

ACC (Accessory). The ACC terminal transmits power to the car accessories like the radio, the lights, the windshield wiper, and many others. The ACC usually has a purple-coated wire.

You must understand which wire goes to where in the ignition switch if you are planning to troubleshoot or replace it. The wire colors will vary depending on your car make and model. Therefore, it’s essential you go based on where the wires are connected instead of the colors. The BATT typically has a red wire, while the other three wires may have green, white, and black colors.

How to wire ignition switch step by step

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 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” (Starter), “IGN”(Ignition input), 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 steering 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 an ignition switch panel wiring diagram for your car.

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.

How to find an affordable car Mechanic

It’s one thing to find an affordable car mechanic and a totally different thing to find an affordable and reliable car mechanic. Here are four proven ways to find affordable and reliable car mechanics and why you should consider any of them.

Contact your dealership

There’s no doubt; car dealerships charge higher than local mechanics. But if your new ride is still under warranty, contact your dealership or extended warranty service provider first.

You’ll pay little to no money if your vehicle is still under warranty. And the best part, the dealership may provide you with proprietary information about the latest technology in your car that the local mechanic may not even be aware of. Plus, you will be assured only the best hands are fixing your car.

However, the dealership will become expensive if your car is not under warranty. Check the other proven ways below if your car or the specific damage is not under warranty coverage.

Ask a friend

Good service advertises itself. Asking a friend could be a game-changer for finding reliable and affordable car mechanics. Imagine you have a good experience with an auto repair shop. Won’t you refer your friend to that shop if he asks? Of course, you will.

Similarly, you’re friend will also recommend you to a reliable auto service center.

Ask a mechanic online.

Let’s get this clear; asking a mechanic online is like going outside the box. Your problem could be a simple DIYer fix that anyone can handle with the right guide. Most online mechanics will answer your queries and even provide guidelines on how to repair the problem without visiting a repair shop. This way, you can fix your car without paying anyone.

Review mechanic profiles

Become your detective. Gather a list of mechanics offering low maintenance and repair service fees and see if they have reviews online. Organizations like Better Business Bureau, APA, CAA, and other reliable sources will show you mechanic service centers with good, bad, and ugly details.

Frequently Asked Questions(FAQs)

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.

What color do wires go to the ignition switch?

The colors of the wires that go to the ignition switch are red, black, yellow, green, purple, white-red, and white-black. The exact wire you’ll find depends on your car model.

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 ground. Once these terminals have been separated from the grounds, the rest of the car’s ignition switch serves mechanical functions.

Can an ignition switch cause the 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.

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 can’t 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. I also recommend that you get a universal ignition switch wiring diagram.

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

2 thoughts on “How to Wire Ignition Switch and What Wires Go to Ignition Switch

  1. Hello Phillip,

    Sorry you have to pass through all that. It’s not easy to spend 2,900 euros on work not done.

    I understand you have a truck diesel engine in your boat. But everything else is still the boat. I may not be able to assist you, as I have not worked on a boat before. I recommend you get a technician that specializes on that boat and explain everything to him. Have an agreement with him, no payment if work is not done.

    Once again, sorry we could not help you on this.

  2. Hi there.
    I own a 22ft colvic sea worker fishing boat with a 2.5 diesel engine without a turbo. I have been told that it s either a Peugeot engine or a old sherpa van engine. but i,m not sure or I can’t be 100% sure. which one of these engines it could be. but I do think it’s an older engine. with the normal heater plugs starter motor and alternator. and the ignition switch I thing has 6 or 7 connectors on the back of it. which has numbers such as 30 in the centre. then (50) (19) (51) etc etc. but there are no letters on the back of it to tell you what coloured wired go where on the back of the ignition switch. but what I can tell you there seems to be a white wire which is permanently live. I think there is quite an heavy cable coming off the solenoid which is green and I think there is also a red cable coming off the solenoid . and the wires that go into the dashboard. (green) (blue) (yellow) ( purple) (orange) (brown) and (black) and there is a pink wire that comes off the fuel sender on the fuel tank to the dashboard also. I had someone in to fix all the wiring, but he took £2.900 off me to do the wiring for me, but never turned up to do the work for me. so now I am left with a lovely boat which I can’t use due to not having an ignition switch connected but all the wiring is hanging from behind the dashboard. so I was wondering If you could help me out on how to wire the ignition switch back in. and tell me what coloured wired go where on the back of the ignition switch . I know that the number (30) goes to the centre post and I think the number (50) post is something to do with the starting side of things. if you can help me out with a diagram diagram or something similar the would be quite helpful to me, but because I have lewybody dementia I find it very hard to take things in, and to remember things. so if you can do me a diagram it would have,to be done in a very simple way for me to be able to understand it. or do you sell recordings of how to wire up ignition switches for inboard diesel engines. this is a car or van engine that has just been marinised to go into a boat. but everything else is a just a normal diesel engine out of a car or van. I look forward to a reply from you.
    Many thanks.
    Phil. TEL (07533985553) at anytime.

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