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Fuel Pump Cut Off Switch

Discussion in 'Electronics' started by ST165-2765, Nov 21, 2007.

  1. ST165-2765

    ST165-2765 Well-Known Member Donated!

    I watched a show recently that said in Canada 500,000 cars are stolen each year and more and more it's older cars that are getting stolen for parts. So since I love my Trac and don't want it stolen I was off to my garage to make a real cheap bit of security for the car.

    This will allow you to disable the fuel pump so even if the thief gets the ignition cracked open and the starter actually wants to crank there will be no fuel to ignite.

    What were going to do is install a hidden switch that will shut of the fuel pump. Once installed my car will run roughly for about 2-3 seconds and then die with no hope of re-fireing without turning the switch back on.

    Parts Required

    - 1 toggle switch
    - enough wire to reach the switch and back
    - a bit of solder & electrical tape or (crimp on wire conectors)
    - wire protector (I used an old piece of clear tubing)

    The first thing you are going to need to do is decide on a location for the switch, I decided to put mine just behind the drivers door because I have to reach back there for the seatbelt anyways.
    In this picture you can see my completed setup. At the bottom of the picture you can see the toggle switch and in the top left of the picture about half way up the drivers side rear wheelwell you can see where I tapped into the wiring harness.

    Here's a closeup of the wire in question. This is a blue wire with a black stripe on it.

    I do not know if this is the best wire to use ? I watched the show and then went and did my mod by just looking at the plug in the back hatch to see what wires went to the fuel pump and then I picked the biggest wire on the plug (normally the biggest wire will be used to carry the supply current).

    So that's it.

    - disconnect the negative battery cable
    - decide on a location for the switch and install it
    - splice into the wiring harness and route your extension wires to the switch. Whenever you are extending a wire allways make sure that the new wire is at least as big as the old wire a bigger wire is better but in most cases is overkill. So if the old wire is 16 guage use 16 guage wire to extend it, 14 guage would be even safer but is probably just wasting money.
    - connect the extension wires to the switch and put some sort of cable protection over the wires (I used some old clear rubber tubing I had lying around, well maybe not so clear…one of the downsides to sandblasting as you can see there is dust and sand everywhere)
    - re-connect the negative battery cable

    The above installation was for an All Trac it has its gas tank located under the spare tire not under the rear seat like ST162's do
    but the installation is the same just different location

    and I know someone's going to wonder why I have 2 big threaded rods sticking out of the trunk

    ST162 fuel cut off switch
    for ST162's the fuel pump plug is under the rear seat

    once again you want the big blue wire with the black stripe, either side 1 or 2 can be used.
    I think wire #3 (small blue) goes to the check connector for the fuel pump bypass

    Toyota has allready provided a nice black tube with a couple unused wires and a plug that run forward
    into the center console so I chose to put my switch under the back of the center console.
    Last edited: May 1, 2012
  2. ST165-2765

    ST165-2765 Well-Known Member Donated!

    Thanks for the inquiry 5678tyui you have brought up an interesting point. My pictures are for an All Trac and an All Trac does not use the same wiring harness as a GT/GTS for the fuel pump/sender unit. An All Trac has the access point in the trunk
    whereas GT/GTS has the access point between the 2 back seats.(2 plugs on the left edge of pic)

    So I will check a GTS fuel pump and let you know which wire your looking for.
  3. ST165-2765

    ST165-2765 Well-Known Member Donated!


    You want the big blue wire on the yellow plug.
  4. sprey16

    sprey16 Well-Known Member

    hey would this count for the same as me ? ive got a gt-r but i guess it is same as the gts? its got a 3sge
  5. ST165-2765

    ST165-2765 Well-Known Member Donated!

    Yeah I think it should be the same for all models except for the All Trac/GT4 which has a differential where you would normally like to put the gas tank.

    So for all models except the All Trac/GT4 the plug/wire you are looking for is in under the back seat cushion in the middle hump.
  6. sprey16

    sprey16 Well-Known Member

    cool thanks i was cleaning there a bit ago and did notice the wires:D tho i wont be doing this mod yet
  7. 5678tyui

    5678tyui Well-Known Member Donated!

    To perhaps overclarify, the following photo has numbers on each blue wire.

    I should think the "1" wire would work, but since the "2" and "3" give me more options on where to place the switch. Which of these (2 or 3) should work? Either one? Just experiment? Thanks.

  8. ST165-2765

    ST165-2765 Well-Known Member Donated!

    Use wire #2.

    Wire #3 should go to the diagnostics port in the engine bay.
  9. 5678tyui

    5678tyui Well-Known Member Donated!

    Awsome, thanks.
  10. mephtar

    mephtar Well-Known Member

    I fianlly got this mod to work, i tryed 2 differnt switched, and ended up using a light switch from a dollar store. Works great, but I need to relocate it still
  11. Jimbo246

    Jimbo246 Guest

    can any tell me where the blue wire is under the dash because i want to mount my switch at the front. Does it just connect to the fuse box?
  12. ST165-2765

    ST165-2765 Well-Known Member Donated!


    The wire will travel inside this plastic tube on the inside of the drivers side door sill from the gas tank to the fuse box. Where it goes from there I don't know.


    If you don't want to do the fuel pump you could always cut the 12volt supply to the ignition coil no spark or no fuel either will prevent starting your vehicle
  13. 86CelicaGT-S

    86CelicaGT-S Well-Known Member

    Ive havent done anything to do with wiring before but when you say splice into the wire could you just find the wire that goes to fuel pump, cut off the surrounding plastic and then connect the toggle wire to the exposed wires ( make like a "T" shape with the two wires. Would that work? Or does the fuel supply wire go into one side of the toggle switch and then out the other side?

    Sorry if this is a dumb question...just trying to figure this out in my head.
  14. ST165-2765

    ST165-2765 Well-Known Member Donated!

    No all you would do in this case is supply 12volts to the switch when the ignition is on but you have no way of stoping the 12volts from getting to the pump.

    Yes you have to cut the wire to the pump and connect the ends to a switch
  15. 86CelicaGT-S

    86CelicaGT-S Well-Known Member

    No all you would do in this case is supply 12volts to the switch when the ignition is on but you have no way of stoping the 12volts from getting to the pump.

    Yes you have to cut the wire to the pump and connect the ends to a switch[/quote:2hma7l8o]

    Oh so basically you just cut the wire in half and put the switch in-between those two wires?
  16. ST165-2765

    ST165-2765 Well-Known Member Donated!

    Yep pretty simple eh ! But your car ain't going anywhere with the switch off.
  17. 86CelicaGT-S

    86CelicaGT-S Well-Known Member

    Yep pretty simple eh ! But your car ain't going anywhere with the switch off.[/quote:4t5bd88j]

    Wow really that's is...huh. Maybe ill be able to do this after all. Thanks a lot :D. :lol: and yeah ill make sure its on before I take off.
  18. mifitso

    mifitso Guest

    i dont know about you guys but i can start my car with a dime or penny. all the thief has to do is get in the car haha.
  19. Jake-89CelicaGT

    Jake-89CelicaGT Well-Known Member Donated!

  20. 86CelicaGT-S

    86CelicaGT-S Well-Known Member

    lol, geez...almost a year since I last posted in this thread. Well I got all the stuff today that is needed to do this just wanted to make sure I'm tapping into the correct wire.

    Also, on my toggle switch there are two connectors...one says "B+" and the other says "Load Charge". Wanting to know if the wire coming from the fuel pump connects to the "Load Charge" connector and the wire coming/going to the battery (or front of vehicle) connects to the "B+" connector.

    Here are some pictures of the wire in question:



    Thanks for any help!


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