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Fuel Pump Cut-off switch?

  • Thread starter Thread starter redterror302
  • Start date Start date Apr 9, 2004
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redterror302

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Apr 9, 2004
#1
  • Apr 9, 2004
  • #1
Hey guys, I was just wondering how I go about wiring in one of these. I want to add some security to my car. I should be able to find a good place for the toggle switch, but do not know what parts I need, or how to wire it. Could someone help me out with this? I would like to install it tomorrow if possible, because I have a few other things to work on as well.

Thanks,
Chris
 
T

TheUser

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Jul 25, 2003
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Apr 9, 2004
#2
  • Apr 9, 2004
  • #2
Jrichker has some good, detailed posts in this...check it out... http://forums.stangnet.com/showthread.php?t=441843
 

89Notch

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#3
  • Apr 9, 2004
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I have a carb so i just put in a hidden switch along the relay wire... Just interrupt the wire and put a switch in somewhere hidden, not too hard at all. The way i figure it's safer to leave the keys in the car w/ the door unlocked but the fuel cutoff, at least that way they won't break anything and they won't get 5' down the road...
 
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redterror302

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  • Apr 9, 2004
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Thanks for the link. So all I need is a switch good for at least 5 amps, and a small amount of 16 or 18 guage wire? Well that sounds easy enough. I guess the hard part will be finding a good place to mount it...
 

393Bird

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Apr 9, 2004
#5
  • Apr 9, 2004
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And to really throw them off, get a old junker pump, and wire it up on one side of a single pole, double throw switch, and the good pump with the gas lines connected to it, to the other side. When you have it in the disable position they will get the sound of the pump, and the car will not get the fuel. Add to there headacks
 
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TheUser

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Apr 9, 2004
#6
  • Apr 9, 2004
  • #6
lol, yeah you could do that, but most theives probably don't try to troubleshoot a car if it's not starting...if it doesn't start, they most likely just leave ASAP. That's clever though.
 

stangbear427

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Nov 11, 2002
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#7
  • Apr 9, 2004
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Here's mine, along with ignition, fan (not hooked up) and licence plate lights
 
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TheUser

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Apr 10, 2004
#8
  • Apr 10, 2004
  • #8
the switches and plate look cool, but I have a feeling it may be noticable If I were gonna use a toggle for security reasons, i'd prob. hide it a little better.
 

stangbear427

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#9
  • Apr 10, 2004
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Unlike most Foxes, my ashtray door isn't broken. I'ts usually closed. So far, no one who has ever moved my car has been able to figure it out, and I always forget to tell them there are other steps to starting it. I don't forsee a problem, it seems even the people who know me and know I would do something like that are too dumb to look around for them. Most people figure there's something wrong with it when it doesn't fire right off.
 
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redterror302

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Apr 14, 2004
#10
  • Apr 14, 2004
  • #10
Alright guys, I didn't have a chance to install it over the weekend, but I did get a switch for it. It is a 20 amp toggle switch, so it should be rated for more than enough current. Now, I know you say the relay is under the seat, but where exactly is it? Is it underneath the carpeting, or do I need to remove the seat? I have the wiring, the switch, and some connectors, just need to get it all together. I will be splicing into the red/black wire, but one quick question, does it matter whether I do it before or after the relay? I was thinking either way would do the same, but does it matter?

Thanks
 
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87'GTstang

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#11
  • Apr 14, 2004
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LOL a switch for the license plate lamps, damn that's clever. I've got that panel in mine also and could never figure out what to make the 4th switch
 

stangbear427

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#12
  • Apr 14, 2004
  • #12
Now you know. I kinda liked the red, orange, green theme too, but no one ever notices that. I guess the blue one throws it off. I think I may take it a step farther though, and have it shut down the whole back of the car not just the license plate lights. Won't make the car go any faster, haven't gotten around to it.

5.0GT- The relay is under the seat, over the carpet. You will probably want to take out the seat, but when you do it'll be sitting right there. Little black box on an L bracket. I couldn't say before or after, Mine goes directly to the pump itself. I would say before the relay though, to be safe. No reason to have it working any more than it has to. On a side note, always make sure you turn it on before you turn the car on. Do it before you even put in the key if it'll help you remember. I forgot a few times and it messed up my computers ignition sequence and I had to clear the memory and re teach it how to start. You don't want to lose your injector priming before ignition.
 

jrichker

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#13
  • Apr 14, 2004
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Repeat performance...

On 87- 91 cars the fuel pump relay is under the seat, 92 and later cars ,the fuel pump relay is under the Mass air duct on the passenger fender well. Cut the red/black wire going to the fuel pump relay. Splice a 16 or 18 gauge wire into the wire and connect it to one side of the switch. Connect the other side of the switch to the other end of the red/black wire going to the fuel pump relay. When you are done the switch should be in the middle of the spliced red/black wire that goes to and comes from the fuel pump relay. Using the inertia switch side of the circuit allows you to use light gauge wire and light duty switches. There is less than 1 amp going through the circuit, so you don’t have to worry about voltage drop across the wiring depriving the fuel pump of electrical power.
 
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madonionrs

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  • Apr 14, 2004
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I have a 89 Fox....

So if I take the driver's seat out of my car. Look for a red/black wireset (only one set?) then cut/splice with a switch that would work?

If so, I'm going to do this.
 
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87'GTstang

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  • Apr 15, 2004
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It's right under there, you really can't miss it.

Would anyone by any chance know the amperage draw for the stock fuel pump?
 

stangbear427

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#16
  • Apr 15, 2004
  • #16
madonionrs said:
I have a 89 Fox....

So if I take the driver's seat out of my car. Look for a red/black wireset (only one set?) then cut/splice with a switch that would work?

If so, I'm going to do this.
Click to expand...
Yes. What jrichker said.
 
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redterror302

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#17
  • Apr 15, 2004
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stangbear427 said:
On a side note, always make sure you turn it on before you turn the car on. Do it before you even put in the key if it'll help you remember. I forgot a few times and it messed up my computers ignition sequence and I had to clear the memory and re teach it how to start. You don't want to lose your injector priming before ignition.
Click to expand...

I am not sure if I understand this. Why would it screw anything up with the ignition sequence? Wouldn't it be the same as if it just couldn't start anyway? It just wouldn't have fuel, therefore won't start. Could you explain to me how it would screw it up at all, not that I don't believe you, I just don't follow it.

Thanks
 
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87'GTstang

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#18
  • Apr 15, 2004
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When the computer is turned on, one of it's paramters is to tell the fuel pump to prime itself. I really see no big effect on it however though due to the fact that when you turn on the fuel pump it will feed pressure to the fuel lines until it reaches a certain pressure then sort of back off and hold. If you do do that though, just wait a few seconds longer than normal before starting the car so that the fuel pump can catch up and have time to build pressure - then everything should be ok.
 

stangbear427

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#19
  • Apr 15, 2004
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Honestly, I don't really understand it myself- and I'm not 100% positive that's exactly what happened- that's just the most accurate explanation I have. Haven't seen anything like it before, not from the fuel injection bank. The EEC in these cars has a pretty sophisticated memory for such a primitive box, and when something isn't doing what it's supposed to it forms habits to attempt to compensate. Once I cleared it, it was fine. However it is usually pretty forgiving of this type of thing, and I really don't understand why it chose to pitch a fit over this. I've never heard of it happening to anyone else, and it probably wouldn't happen to you- but I thought I'd mention it to be safe, even though I haven't quite figured out what the problem was. The punchline is at the end of that post- make sure it has a chance to prime before you crank it. I have seen GM's develop drivability issues that got to the point where they wouldn't start from not doing this. It's important. Only takes a second or two, you should even be able to hear the pump spinning when you turn it on while it primes. No biggie.
 
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redterror302

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#20
  • Apr 15, 2004
  • #20
I see what you guys are saying, thanks for the help. I just wanted to find out what you really meant, because I obviously wanted to try it to make sure that it worked properly. I know that the fuel pump shouldn't prime at all, but I just wanted to crank it to make sure it wouldn't start.

Thanks again for the help.
 
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