Here's a fun project that I did to my very first car. When I first got it I was quite happy with my purchase, but soon after that I found that I really wanted a sweet push button ignition and an engine kill switch, like a rocket or a race car or something cooler than an early nineties economy car. Well, it has been nearly a year and today i tore apart my dash, cut up some wires, soldered and drilled and figured and puzzled for about 5 hours and now, the final result, you will see in this instructable.
I'll show you how to wire in a push button ignition and an engine kill switch in your car. It's easy, as I have done all of the puzzling and figuring for you. It should take between one and two hours, depending on how fast you can take apart your dashboard, but could take considerably longer. This project cost me like 25 bucks for a soldering iron, wire, one relay, two momentary buttons, and a switch. If you have some of these it will be cheaper. Either way, this is a small price to pay for such a cool feature.

Step 1: Gather Materials

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The Button.JPG
The Switch.JPG
For this project you will need:

One Single Pole Double Throw Relay (a SPST normally open will work as well)
One Momentary switch, Normally open (toggle or button)
One Single Pole Single Throw Switch (toggle or button)

Soldering Equipment/Knowledge
Wire (I used 18 g)
Wire Cutter
Other various tools

Be sure that whatever momentary switch or button you get is a normally open, momentary switch.
anything else will not work for what we need.

Step 2: Open Up the Dash

Picture of Open Up the Dash
Here you will need to get inside your dashboard to where your ignition harness is. This is near the keyhole. Once you get to this bundle of wires you will need to cut the Ignition Wire and the Starter wire, so also disconnect the battery first. You will have to find a wiring diagram for your car to know what wires do what. I can tell you that for Hondas the Ignition wire is black and yellow, and the Starter wire is black and white.
Cut these wires and strip the end enough that you can solder it or splice it well.

Just a caution, this step, more than any others so far, has a potential for really messing up your car. as long as you cut the wires such that you can splice or solder them back together you should be ok, but be aware that cutting wires to your ignition could become a problem.

Step 3: Assemble the Hardware

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Relay again.JPG
Relay Circuit.JPG
Now we will solder together the chain of switches and wires and buttons and relays to make this all work. This is by far the easiest step.
Basically the way this all works is that the Ignition wire, which needs to remain a closed circuit as long as the engine is going is connected to the relay, and we will borrow some of the current going through it to switch the relay and start the engine. Solder the wire ends to the Ignition wire or the starter wire as indicated.

Step 4: Put it all under the dash.

Picture of Put it all under the dash.
Panels Popout.JPG
Now that your parts and wires are all wired in its time to test it. Turn the key to the "Engine On" position. Flip the switch on. Push the button. If you have wired everything all correctly you will start the engine. Now put your dash back together and put your buttons and switches wherever you like. You can drill holes in the dash and put the button and switch through there, or you can hide it under the dash.

Step 5: Show it off to your friends

Picture of Show it off to your friends
Alright! now you have a push button ignition in your car, just like all the high end sports cars, rocket ships, and computers. Go ahead and show it off, thats what you did it for, right? Be sure to post a picture here so we all can see it.
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okay so there is no need to do all of this... you basically need two 3 switches in total and you will not need the key to start only to unlock the steering wheel. you will cut out the ignition switch completely! Get 2 rocker switches with at least 30AMPS and one push button. Rewire the ignition wires to the switches. One switch will be to turn on ACC then, the other to go to IG1 and IG2. Then the push button will work as your starter! look at my youtube video below with the actually system at work.
Do you have a how to video of this?
zack2473 years ago
you should be able to just splice some wires into the ignition wires, so you can still use the key or the button to start the car. that way its still startable should something go awry with the new ignition system
That and keep the steering lock from engaging in cars that have it
that too, i know my car locks up the wheel without a key in the ignition.
so do i connect the starter wire directly to one switch and the ignition to the other switch? then from the switch to the relay
so what color wires from the ignition key go where on the relay?? still confused
hurbina4 years ago
on the drawn figure wouldnt the momentary button wire be 86 and the one with the toggle be 30 and the and the looped 85 and the bottom right 87.
Can you label which terminal is which in your "inside spst" and which terminal and which goes where? It seems like you have a fith terminal though but Its hard to tell.

This is what I though

Bosch usual relay - on fig 3 (inside spst relay)
#30 bottom right
#85 top left
#86 Bottom Left
#87 top right

#87a Is not shown

demonas6 years ago
why relay? isnt there simplier way? Or maybe I dont understand something...
jpayton demonas4 years ago
The relay has a higher tollerance than the switch. and is less likely to fail. (if it fails your engine dies, loosing power steering and brake assistance. small car thats not a big deal but if you have an SUV or truck or are hauling your going to have a stoping adventure. lol
punx777 jpayton4 years ago
Agreed. There are many relays in your car. Supporting those high amperage lines may be too much for a little switch to handle all the time.
jpayton4 years ago
You should use solderless crimp connections in any auto application. especally wires. As the wires bounce the solder cracks and loosens. Crimp connecters have plenty of give. If one of thoes wires breaks loose. Should use an automotive relay as well. They just have stronger coils.
superdean6 years ago
do i need to use a One Single Pole Double Throw Relay... wat does it do
It seperates the small switched for the possable 20amps the ignition can draw.
fredyakaoso4 years ago
in the wire drawing you didnt label a wire coming of the relay (button left) to what does it connect?
fredyakaoso4 years ago
Hall 9000 Can you please post a schetmatic for this project. PLEASE!!
ghostrider27 years ago
I have an interesting idea for a car engine. does anybody have any idea how you could modify a car engine to run off oxygen removed directly from he air around the car, basically making gasoline useless? I know it sounds too much like science fiction, but I think it could be possible. I have some idea of a design, but I don't have any solid ideas. any automotive engineers that could help me?
The closest thing you can get is a hydrogen generator which uses electricity to split H and O in water to make a combustible gas but no one really has an engine that works off straight hydrogen like that (not yet any way.) look for HHO or hydrogen generators and you can find kits that you put in current cars to up your gas milage.
I would use a hydrogen generator to because they make the oxygen and the hydrogen the only problem is they don't make it very fast. The way to solve this is to let it run overnight perhaps and have a system to compress it so it could be stored in a tank in the trunk or something. Then you would have to design a system to keep it from backfiring because the gas will start to burn before it enters the cylinder.
The hydrogen gas should not burn before it enters the cylinder because the spark plug ignites the gas when the intake valve is closed.
They can if you pump heaps of amps into them
However the car cannot supply enough power alone so yes it can work fast just it would be another energy bill to pay. On a separate note there is probably an optimum efficiency so you can get the most hydrogen per amount of amps applied. This in a sense is similar to using good driving habits to get the best mpg.
yeah but after that you get a lot of problems like compressing it storing it in a safe container ( if you get in a crash with a badly installed hydrogen car you get big boom )
wupme downgrade6 years ago
Well i think most 4 stroke engines would work with hydrogen. You just need a different carburetor. But those hydrogen generators don't create enough hydrogen for a car engine to run.
oxygen is the catalyst that allows a fire to burn. without a fuel source i.e gasoline, kerosene etc. it wil not ignite. like most of the other people have said oxygen is just what allows the fire to burn and is not actually what ignites the fire. think about it for a second. have you ever threw a blanket over a fire or maybe threw dirt on a fire? what that does is smother the fire. in other words it takes the oxygen out of the area where the fire is burning and causes it to extinguish itself. therefore if you try to make an engine run just on O2 it will simply not work.
Sorry buddy, but you still need fuel. Oxygen just allows fuel to burn. For example a hard candy such as Jolly Ranchers don't burn normally, but in pure oxygen they do. The sugar in the candy is combustible.
no regular "air" dose not burn pure oxygen dose burn. Why do you think that you cant smoke around old ladies that are breathing compressed air?
yeah.. pure oxygen does burn... buuuutttt in normal air oxygen exists as 02 its more stable form. if you can pull flammable oxygen out of the air, then smoking anywhere would ignite all the surrounding oxygen molecules
Pure Oxygen does not burn! It just supports combustion, meaning stuff burns EASIER. And Oxygen in the atmosphere is not 2%, it's approx. 20.946%, by volume.

By the way... If oxygen did burn, what do you think would have happened to our atmosphere?

Just to prove it to you...
Link - Down near the bottom
Link - Another source
Link - Yet another source
I understand your short mind. O2 does not burn - O2 is what is found in the atmosphere - O1 is a different form of oxygen which is also never found in the atmosphere(maybe for fractions of seconds during chemical reactions but thats it)however O1 indeed would burn if you could keep it stable long enough to enter the engine. Which would just cause a backfire from bad ignition.
please dont call padlock short minded it makes you sound more stupid that necessary. oxygen is the name given to a chemical know as O2 ozone is O3 they both exist in the atmosphere. O1 doesnt simply because the O1 would react with the neares chemical molecule that is near it.
now to tackle oxygen burning. it DOESNT burn do some research oxygen got its name because its a very good oxidizer (oxygen and oxidize sound similar dont they) now all form of cumbustion is an extreme form of oxidizing where there is a fuel and an oxidizer to put it simple read what padlock said but if your not convinced please show me your evidence of oxygen ever burning. by the way what flammiblity  class is oxygen in you can see it on the containers that it comes in when u find that please let me know
HAL 9000 (author)  dpsilver5 years ago
 Actually the word "Oxidation" comes from "Oxygen," not the other way around.
thanks for the info bro btw why havent you corrected these people going around talking about oxygen burning 
HAL 9000 (author)  dpsilver5 years ago
It's impossible to stop. Where there is internet, there is people making trouble over insignificant stuff. I can't help it if i wanted to, i wouldn't help it even if i could.
hey i like the instructable but is it possible that i can use a the same button to kill the engine as well like a engine start/stop button that woul be cool 
 You could use a toggle on/off button instead of the toggle on off switch but it would be nearly impossible to use the same button with analog wiring.  I will also assume that neither of us can to it in digital code.
The definition of burning is this: To be on fire; undergo combustion. A substance burns if it is heated up enough to react chemically with oxygen. Oxygen cannot react with itself!
O2? That is how oxygen exists in our atmosphere. If it doesnt react with itself then how did do that?
Exactly. Pure oxygen (O1) is extremely unstable and will react with many things including itself. The original topic was an engine that could concentrate oxygen from the air to use as fuel in an ICE (Internal Combustion Engine). I said it was not possible, because oxygen that exists in the air is very stable. O1 is very unstable and would work as fuel for an ICE, but to create it would require the same amount of energy that it would produce when "burned". The only thing that an air oxygen purifier (O2 purifier) would do, would be to act like a turbo or super charger. Concentrated oxygen in the engine would allow for more fuel such as gasoline to be pumped in. This satisfies Limiting Reactants, by having an equal ratio of O2 and fuel. Oxygen from the air (O2) supports burning, but itself cannot be burned. Simply concentrating it would allow for more fuel to be burned at once.
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