DIY: Using a Factory Dash Button as a Fuel Pump Cutoff
01-04-2015, 02:42 PM
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DIY: Using a Factory Dash Button as a Fuel Pump Cutoff
It's like push to start x 0.5
This is my write-up on how to turn an unused button or switch on your dash into a fuel pump cutoff switch.
You're going to need:
-A relay switch that can handle 20A or more
-18 gauge electrical wire
-Soldering Gun/ solder
-Wire scrippers
-Heat shrink tubing or black electrical tape
-A factory button or switch in your car that is unused or you're willing to sacrifice (must toggle)
You're going to want:
-A 12v voltage tester (probe with light bulb that glows when you touch a powered wire)
-Creativity
-A sense of general cheekiness
-Beer
-Babes
Did your car come with cruise control from the factory but your sick JDM swap doesn't use it?
You deleted your A/C?
You deleted your rear wiper?
You deleted your browsing history?
Most of these are possible reasons why you might have a factory button on your dash that you don't use anymore. At the seemingly constant rate of which 89 Accords are getting stolen from strip malls, Installing a fuel pump cutoff switch in your car is an easy-to-do, easy-to-use added security measure that at the very least is going to annoy the **** out of a smart thief.
A lot of people choose to just buy a switch from Walmart, splice the fuel pump power wire, and cram that bish under the carpet. But now you have to pull your carpet up every time you want to make use of the switch. Using a stock button or switch on your dash can be just as secretive, but easier to use. And pretty slick. But, going this route requires a little more effort. You are probably going to need...
A relay.
You see, that fuel pump in your civic needs a decent amount of Amps to run. In my EF civic, it requires 20 amps at 12volts.
That little switch on your dash probably runs at 10 amps or less, or it already runs through a relay in stock configuration.
What is a relay? Think of it as a big brother switch that runs off a smaller switch. It's a phat switch that's turned on or off by a little wimpy one that can't handle all that power.
The relay you're going to need should be rated at 30 amps or higher (Has to have a higher amp rating than the amps of the fuel pump). Mine is from my old Saturn that dropped a valve
They come with 4 pins or 5 pins. Either one will work.
Okay, so let's get started.
First find the button or switch on your dash you wanna use, and expose it to the point that you can remove the switch and access the wires that run to it.
The black and yellow wire that runs to your switch is the power wire. It supplies electricity to the switch only when the car is on or ACC is on.
Leave the YLW/BLK connected to the switch, and snip the rest. Leave at least 3 inches of wire on either end so you can reconnect wires later. If you don't see a YLW/BLK wire anywhere, you're going to have to look up which wire is power, or use a voltage tester (lightbulb that glows when you touch power) to touch each bare wire until you find which one receives power when you turn the car key from off. Leave the power wire connected to the switch and snip the rest.
Turn the switch on, turn your car key on, and voltage test the other wires coming off the switch until you find which one gets power when the switch is on, and loses power when the switch is off. Mark this wire or remember its color. We'll call it the sender wire (The power wire receives power, the sender wire sends the power after the switch is on).
-Disconnect your battery
Now, locate your fuel pump. It is inside of the car, above the fuel tank.
Trace the wires coming off of your fuel pump. Keep following where they go until you're under the carpet, and/or in a spot where you can hide the snipping and soldering you're about to do to these wires. In this location, snip the Black/Yellow wire (power) and remove a small section of plastic from the black wire. Do not snip the black wire. You are just going to add another wire onto it. (Ground).
So now you have 4 wires that are ready to be connected to.
1. "Sender" wire end from your dash button/switch ( sends power when switch is on).
2. Black/ Yellow wire end coming FROM the fuel pump (connected to the fuel pump still).
3. Other end of the same Black/ Yellow wire, running TOWARDS the fuel pump (not connected to fuel pump).
4. The exposed portion of Black wire (ground).
Numbers 2, 3, and 4 should all be in locations where no one is going to see that you messed with any wiring, and also, as close as possible to where you are going to hide your relay.
Now, take your relay, and place it in the spot you are going to hide it. Take your roll of wire, and run it from a wire location (listed above) to the relay. Snip this length off your roll, and label it 1, 2, 3, or 4, according to the list above ^^^^. Essentially you're mocking up the wiring and "measuring" the 4 wire lengths you're going to need.
Remember to consider that you are going to want all of these wires hidden, you need to mock them up the way you are going to route/ tuck them when you cut their lengths. I leave my #1 wire (wire from your switch to the relay) extra long so i can route and tuck it easily.
Got your 4 wire lengths cut and labeled? good. Now go have a beer or three and watch a couple Regular Car Reviews on YouTube.
You're back? Okay, well we're almost done.
Take your 4 wires and the relay and go to your soldering station.
Here is a diagram of a common relay switch:
Wow. Such confusion.
But not really. If you can't understand the diagram that's fine though, I'll simplify it for you:
Your relay should have 4 or 5 pins on it. Each pin has number by it. A 5 pin relay has an "87a" pin, a 4 pin relay does not. You won't be using this 87a pin either way so tape it off/ shrink tube it now if you have it.
-Solder your #1 wire to pin 86.
-Solder your #2 wire to pin 87.
-Solder your #3 wire to pin 30.
-Solder your #4 wire to pin 85.
Now, cover up each of these pins on the relay with some black electrical tape.
With this wire/ relay mess in your hand, start walking towards your car. Stop. Grab a beer. Continue walking towards your car.
Put the relay in the spot you are going to hide it, and secure it there. Make sure it's not going to get smashed or something.
-Route/tuck and then solder the other end of wire #1 to your switch/button you are using (solder to the switch's "sender" power wire, the wire that sends power only when the switch is on.)
-Solder the other end of wire #2 to the black/ yellow wire that is connected to the fuel pump.
-Solder the other end of wire #3 to the black/ yellow wire that runs towards the fuel pump but isn't connected to it.
-Solder the other end of wire #4 to the little portion of exposed wire you made on the black wire (ground).
Cover all of your new connections and solder welds with black electrical tape or heat shrink. You don't want **** starting on fire, and you don't want this system to fail ever lol.
Reassemble all of the interior you took apart. Make sure everything looks like it did before you started any of this. Make sure the relay, new wires and connections are all hidden and secure!
-Reconnect your battery
Grab a beer. You're done!
To test it out, turn the switch "on" (whatever "on" is on your switch
). Try to start your car. You should hear the fuel pump hum for a moment prior, and your car should start.
If you turn the switch off and then try to start your car, you shouldn't hear any noise coming from the fuel pump. No hum. The car won't start because it isn't getting any fuel from the dead fuel pump!
At this point, you can add a fuse to the system for extra safety if you want to.
*You can also add as many switches as you want, in series, to the #1 wire. Then you'll have a rare JDM combination of switches and things that have to be in the right place before the car will start (extra cheekiness).*
Note: since the activation of the fuel pump happens at the same time you turn the keys, you have to have your switch "on" before you turn the keys at all. If you have your radio or lights on, and then turn your switch on, you will hear the relay click, but the priming of the fuel pump won't happen because that's not how the ECU is programmed. However, when you car is running, hitting your switch from on to off will kill the fuel pump and the car will die in a couple of seconds.
Well, there you go. If anything here is incorrect or different for you please feel free to comment, as this is all based off my experience of doing this procedure on a friends car
. I know pictures would give you a lot less to read, but if you can determine wire colors and follow these steps in order, you shouldn't have much difficulty.
This is my write-up on how to turn an unused button or switch on your dash into a fuel pump cutoff switch.
You're going to need:
-A relay switch that can handle 20A or more
-18 gauge electrical wire
-Soldering Gun/ solder
-Wire scrippers
-Heat shrink tubing or black electrical tape
-A factory button or switch in your car that is unused or you're willing to sacrifice (must toggle)
You're going to want:
-A 12v voltage tester (probe with light bulb that glows when you touch a powered wire)
-Creativity
-A sense of general cheekiness
-Beer
-Babes
Did your car come with cruise control from the factory but your sick JDM swap doesn't use it?
You deleted your A/C?
You deleted your rear wiper?
You deleted your browsing history?
Most of these are possible reasons why you might have a factory button on your dash that you don't use anymore. At the seemingly constant rate of which 89 Accords are getting stolen from strip malls, Installing a fuel pump cutoff switch in your car is an easy-to-do, easy-to-use added security measure that at the very least is going to annoy the **** out of a smart thief.
A lot of people choose to just buy a switch from Walmart, splice the fuel pump power wire, and cram that bish under the carpet. But now you have to pull your carpet up every time you want to make use of the switch. Using a stock button or switch on your dash can be just as secretive, but easier to use. And pretty slick. But, going this route requires a little more effort. You are probably going to need...
A relay.
You see, that fuel pump in your civic needs a decent amount of Amps to run. In my EF civic, it requires 20 amps at 12volts.
That little switch on your dash probably runs at 10 amps or less, or it already runs through a relay in stock configuration.
What is a relay? Think of it as a big brother switch that runs off a smaller switch. It's a phat switch that's turned on or off by a little wimpy one that can't handle all that power.
The relay you're going to need should be rated at 30 amps or higher (Has to have a higher amp rating than the amps of the fuel pump). Mine is from my old Saturn that dropped a valve
They come with 4 pins or 5 pins. Either one will work.
Okay, so let's get started.
First find the button or switch on your dash you wanna use, and expose it to the point that you can remove the switch and access the wires that run to it.
The black and yellow wire that runs to your switch is the power wire. It supplies electricity to the switch only when the car is on or ACC is on.
Leave the YLW/BLK connected to the switch, and snip the rest. Leave at least 3 inches of wire on either end so you can reconnect wires later. If you don't see a YLW/BLK wire anywhere, you're going to have to look up which wire is power, or use a voltage tester (lightbulb that glows when you touch power) to touch each bare wire until you find which one receives power when you turn the car key from off. Leave the power wire connected to the switch and snip the rest.
Turn the switch on, turn your car key on, and voltage test the other wires coming off the switch until you find which one gets power when the switch is on, and loses power when the switch is off. Mark this wire or remember its color. We'll call it the sender wire (The power wire receives power, the sender wire sends the power after the switch is on).
-Disconnect your battery
Now, locate your fuel pump. It is inside of the car, above the fuel tank.
Trace the wires coming off of your fuel pump. Keep following where they go until you're under the carpet, and/or in a spot where you can hide the snipping and soldering you're about to do to these wires. In this location, snip the Black/Yellow wire (power) and remove a small section of plastic from the black wire. Do not snip the black wire. You are just going to add another wire onto it. (Ground).
So now you have 4 wires that are ready to be connected to.
1. "Sender" wire end from your dash button/switch ( sends power when switch is on).
2. Black/ Yellow wire end coming FROM the fuel pump (connected to the fuel pump still).
3. Other end of the same Black/ Yellow wire, running TOWARDS the fuel pump (not connected to fuel pump).
4. The exposed portion of Black wire (ground).
Numbers 2, 3, and 4 should all be in locations where no one is going to see that you messed with any wiring, and also, as close as possible to where you are going to hide your relay.
Now, take your relay, and place it in the spot you are going to hide it. Take your roll of wire, and run it from a wire location (listed above) to the relay. Snip this length off your roll, and label it 1, 2, 3, or 4, according to the list above ^^^^. Essentially you're mocking up the wiring and "measuring" the 4 wire lengths you're going to need.
Remember to consider that you are going to want all of these wires hidden, you need to mock them up the way you are going to route/ tuck them when you cut their lengths. I leave my #1 wire (wire from your switch to the relay) extra long so i can route and tuck it easily.
Got your 4 wire lengths cut and labeled? good. Now go have a beer or three and watch a couple Regular Car Reviews on YouTube.
You're back? Okay, well we're almost done.
Take your 4 wires and the relay and go to your soldering station.
Here is a diagram of a common relay switch:
Wow. Such confusion.
But not really. If you can't understand the diagram that's fine though, I'll simplify it for you:
Your relay should have 4 or 5 pins on it. Each pin has number by it. A 5 pin relay has an "87a" pin, a 4 pin relay does not. You won't be using this 87a pin either way so tape it off/ shrink tube it now if you have it.
-Solder your #1 wire to pin 86.
-Solder your #2 wire to pin 87.
-Solder your #3 wire to pin 30.
-Solder your #4 wire to pin 85.
Now, cover up each of these pins on the relay with some black electrical tape.
With this wire/ relay mess in your hand, start walking towards your car. Stop. Grab a beer. Continue walking towards your car.
Put the relay in the spot you are going to hide it, and secure it there. Make sure it's not going to get smashed or something.
-Route/tuck and then solder the other end of wire #1 to your switch/button you are using (solder to the switch's "sender" power wire, the wire that sends power only when the switch is on.)
-Solder the other end of wire #2 to the black/ yellow wire that is connected to the fuel pump.
-Solder the other end of wire #3 to the black/ yellow wire that runs towards the fuel pump but isn't connected to it.
-Solder the other end of wire #4 to the little portion of exposed wire you made on the black wire (ground).
Cover all of your new connections and solder welds with black electrical tape or heat shrink. You don't want **** starting on fire, and you don't want this system to fail ever lol.
Reassemble all of the interior you took apart. Make sure everything looks like it did before you started any of this. Make sure the relay, new wires and connections are all hidden and secure!
-Reconnect your battery
Grab a beer. You're done!
To test it out, turn the switch "on" (whatever "on" is on your switch
). Try to start your car. You should hear the fuel pump hum for a moment prior, and your car should start.If you turn the switch off and then try to start your car, you shouldn't hear any noise coming from the fuel pump. No hum. The car won't start because it isn't getting any fuel from the dead fuel pump!
At this point, you can add a fuse to the system for extra safety if you want to.
*You can also add as many switches as you want, in series, to the #1 wire. Then you'll have a rare JDM combination of switches and things that have to be in the right place before the car will start (extra cheekiness).*
Note: since the activation of the fuel pump happens at the same time you turn the keys, you have to have your switch "on" before you turn the keys at all. If you have your radio or lights on, and then turn your switch on, you will hear the relay click, but the priming of the fuel pump won't happen because that's not how the ECU is programmed. However, when you car is running, hitting your switch from on to off will kill the fuel pump and the car will die in a couple of seconds.
Well, there you go. If anything here is incorrect or different for you please feel free to comment, as this is all based off my experience of doing this procedure on a friends car
. I know pictures would give you a lot less to read, but if you can determine wire colors and follow these steps in order, you shouldn't have much difficulty.
01-04-2015, 03:48 PM
#2
Honda-Tech Member
Re: DIY: Using a Factory Dash Button as a Fuel Pump Cutoff
Good write-up for the first-timer. Also good for killing just about anything that makes the car run!
01-06-2015, 12:50 PM
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Re: DIY: Using a Factory Dash Button as a Fuel Pump Cutoff
thanks for the write up. i've been looking for something like this for a couple days now. Im going to purchase a civic and my worst fear right now is it being stolen with the neighborhood i live in ,,
quick question. so say the switch is like a light switch that flicks for example. now say i have 5 switches i would have to flip all of them any number at a time? like the pattern for when hitting the switch or button .
once again thanks. man did i have the only brain fart trying to figure all this stuff out. im overwhelming myself and i dont even own a civic yet lol
quick question. so say the switch is like a light switch that flicks for example. now say i have 5 switches i would have to flip all of them any number at a time? like the pattern for when hitting the switch or button .
once again thanks. man did i have the only brain fart trying to figure all this stuff out. im overwhelming myself and i dont even own a civic yet lol
01-10-2015, 09:38 PM
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Re: DIY: Using a Factory Dash Button as a Fuel Pump Cutoff
thanks everyone! glad to help.
No prob! yep, if you use more than one switch, just connect them all in series (one after another; power - switch - wire - switch - wire - ). When the first switch is on, it will send power thru to the next switch, and stop there until that switch is turned on too. If you plan on using flipping style switches you will probably want to hide them, if this is the case you can just buy a bunch of 20 or 30 amp switches from wal-mart and skip the relay part.
thanks for the write up. i've been looking for something like this for a couple days now. Im going to purchase a civic and my worst fear right now is it being stolen with the neighborhood i live in ,,
quick question. so say the switch is like a light switch that flicks for example. now say i have 5 switches i would have to flip all of them any number at a time? like the pattern for when hitting the switch or button .
once again thanks. man did i have the only brain fart trying to figure all this stuff out. im overwhelming myself and i dont even own a civic yet lol
quick question. so say the switch is like a light switch that flicks for example. now say i have 5 switches i would have to flip all of them any number at a time? like the pattern for when hitting the switch or button .
once again thanks. man did i have the only brain fart trying to figure all this stuff out. im overwhelming myself and i dont even own a civic yet lol
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02-06-2015, 02:26 PM
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Re: DIY: Using a Factory Dash Button as a Fuel Pump Cutoff
Had a friend who did this and used the remote turn on wire of his radio as his switch... Then one day, someone stole the faceplate of his radio from his car. Would've been nice if he had a small set of tools on him at that moment...
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