I am wiring up a fuel pump cut off switch, and need to know if I am doing this right. I spliced into the large black wire going to the fuel pump. I am assuming (after reading the manual) that this is the ground for the fuel pump. First off is this the right wire. Second, what kind of switch can I put on it? Can i use a basic on/off switch with a amp rating of 10? It is my understanding that since it is on the negative side, there is no current running through it. Do I need a higher amp switch?

Thanks

 

that should be fine.

 

Maybe i'm just an idiot but why would you want to cut off the fuel?

 

A hidden fuel pump cut-out is a great anti-theft device. At least any theaves wont be able to take a joy ride in your car.

 

Damn, all this time on the forum and my first double post ever. Forum lag pisses me off

 

Exactly, that is why I am logged in under an ussumed name. I am using it as a antileft device. If the switch is well hidden, there is no way that the theif can start your car.

So the forum concensus is that I should be fine.

 

Hook a multimeter up to it... I think you'll be surprised.

A high current accessory like an amplifier, fog lights, or a fuel pump requires a 12V relay if you wish to interrupt the power supply. A low voltage switch is not sufficient by itself.

 

Wish that was true
a Smart thief would soon relise what is going on. The fuel cut off switch is an old trick used by alot of guys.

the guys that do it just dont put a switch in there, that would be to easy to override. All they would have to do is Cut and splice there own wire to the end of the stock wire. and then shes all ready to run.
Trust me, it has been done there are plenty of people who still get there car stolen today w/ that "trick" installed.
The best route would be to add a secound relay past the first realy. Just dont add it in a series add it some where far away.

So, if they try and splice ..no workie the seond realy is not activated. They either got a lot of work ahead of them or give up.

Btw, only tell those whoe drive the car.
friends of freiends of friends could careless about you
just lookin out!

 

Good Idea, I might do that someday!

 

I know it is an old trick, but it does help divert the untrained theif. A real theif would jsut tow the car away and forget about breaking into it. Do you have any more infor on the second method that you mentioned? I guess I could just pull the fuel pump relay or fuse, this would also help. Since the car is a weekend car, this wouldn't be that hard to do when I am not driving it. I am more worried about it when it is sitting.

 

keep everything stock, wires realys everything.
Now splice into the normal wire from the original realy
snake it up to your hidden secound realy. To actiave the realy use a small switch hidden somewhere safley inside the car. Then after the realy snake the wire back to the orginal but not out in the open. Splice it back somewhere in a underclosed spot.

there is a lot of variations you could do. Such as, leaving the stock realy where it is but totaly cut it out of the system and route everything back your your hidden relay. So, everything looks in order but its not.

The basic prinicpal is to keep the thief guessing and stop him from taking the car.

I wouldnt worry to much, keep it in your garage get lowjack just incase and tell no one about your changes.

 

If your going to do this sure you can hide a switch but you need a relay close to the splice. The purpose of a relay is to limit the extra length of wire needed to get the switch close to you or anywhere you chose to put it. The longer length of wire is only caring the amperage load of the relay. If you hide everything well it will keep most all bad guys away. I can't see a guy braking out a volt meter or a test light to diagnosis the reason the car he is trying to jack wont start. I believe the best way to disable a engine is to kill the injector power feed. You can here a fuel pump running thus you can tell when the pump is in op. You can see a coil not firing as well, but an injector pulse not so easy. There is only one power feed to the injectors so its just as easy but use a relay a good one as well. They don't pull as much as a pump but you don't want a voltage drop at the injectors as we all know what a lean mixture will do. I rewired my injectors from the injector to the ECU with larger cable and installed a relay to run the power feed. I did this because I had a 3K hesitation. It didn't fix the problem. I am convinced its a lean conduction and it just happens to be where you may cruse on the freeway or close to it if you were doing around the speed limit in 4 or 5 gear. I think its programed to run its leanest mixture there to enhance emissions and fuel mileage. I think the set up is cutting it so close that a number of factors, grounds, restricted injectors etc just expose the mixtures small envelope and the engine starves for fuel. Just an opinion.

 

I hate to bring this old thread back, but I didn't wanna start a new thread. I wanna wire in a similar switch as well. I have a heavy duty 20 amp switch, would that be adequate to supply amperage to the pump without a relay? I dont want to in any way create a voltage drop, and create starting/running issues.

 

yep a 20 amp would do . i did this today and it works like a charm and also if u ever flood up ur engine its good to have

 

You don't need an additional relay if you run your switch so it interrupts power to the coil in the circuit opening relay.

 

Ok I tried this just now, and again the car doesn't start with the switch wired in. I checked the resistance of the switch, and its 20 ohms WAY too much resistance there. This is really frustrating and complicating when it should NOT be. Does anybody know where I can find a switch that will handle 20 amps, but have VERY low resistance?

 

nvm I found exactly what I was looking for after a lot of research

 

I have my fuel pump rewired and integrated a kill switch. Here's how I have mine wired up. I have the kill switch on the "signal" wire that activates the relay. It uses an illuminated rocker switch, so it lights up when the power is on.



oh and P.S. i have my signal tapped into the cigarette lighter for power, but you don't have to do that...you can tap into the existing power that goes to the pump or any other power source that comes on when you turn the key forward.

 

great diagram , it should be archived ! but i did the same thing a few days ago.

 

where is the fuel cut off relay and does it have 6 prongs or 8.thanks guys.

 

anyone here

 

just hook a toggle switch in-line from the factory fuel pump/circuit opening relay trigger. no relay needed. you're basically turning off the factory fuel pump relay completely. this is a common mod on 2nd gen cars as an anti flooding method. On my FC I had my fuel cut switch hooked to a factory auto adjusting suspension switch. So when I hit the "sport" button the fuel pump would work, and when I hit the "normal" button it would not work.

 

Fuel cut off switch to band aid the rotary flooding problem

 

or if you read the original post you'll see that wasn't the intention of this thread...

 

just replying to the third post bro