ok i already know how to do this, with the pump wire behind the steering column up under the dash, but i was cleaning out my car today, and theres a switch in the armrest lid, i followed it back to the part of the wiring harness that goes into the fuel pump in the back. so i figured it was a fuel cut switch (my car RARELY floods) but the switch was busted. so i went out and bought a new replacement switch (glow toggle switch with 3 prongs, ground/on acc./voltage) but it doesnt light up, and when i switched it, it does nothing... i was thinking about it and i guess it doesnt have a power source, thats why it isnt lighting up, but anyways has anyone ever heard of this way of wiring up the fuel cut switch?

i can take some pics if no one knows what exactly im talking about but its pretty obvious of the location of the wiring harnes that its going into in the back.

 

In order to get the switch to light up, I think you have to ground it. I think you connect the ground to the third prong (not the power or acc).

 

uhhh, thanks but thats common sense... i know!

the problem is that i dont think, actually i KNOW that the other 2 wires which are the ones coming from the harness has no power wire. thats why im asking if anyone has ever heard of wiring up a fuel cut switch like this.

 

bump

 

Toggle switches with lights are a little different then standard switches. The lighted toggle needs a 12V source, ground and has an output. When the switch is "on", the output puts out 12V. When it's off, the output is at 0V.

For a fuel cut switch, you need a regular SPST non-lighted switch.

If the wires go to the fuel pump, they should just be an extension of the fuel pump +12V wire (um, black with red stripe I think).

 

cool, let me go check on what the colors are exactly, but the switch that was in there was already a lighted one, so thats why i bought the same thing... maybe they didnt know what they were doing?

 

Most people who modify a car's electrical system don't know what they're doing.

If they just connected the wires to the 12V and output, then it should have worked.

 

ok it looks like they spliced the black wire into the switch (im guessing thats the power wire?) meaning theres no 12v source for it to work right?

 

The black wire is actually the ground. I doubt this switch had any effect, since the fuel pump is still grounded through the flange and tank.

The blue wire is the power lead for the fuel pump, and is the one that should be switched (according to my Haynes manual).

 

damn what a tool... so is there any way to make this work with the blue wire and with the light up switch at the same time?

 

Ya you want to cut into the blue wire. That seems to be the only wire with any real effect. I pulled out all the other wires from the connector to see which one had any effect and the blue wire was the only one.



Justin

 

would something like this work?

 

I don't like adding the switch at the fuel pump wires. To get the switch to a convenient location you need to add 7-8' of extra wire to the circuit, which increases voltage drop. Installing the switch at the circuit-opening relay by the steering column and putting the switch in the panel under the steering column with the little vent only adds 9-10" of wire.

 

well i could always do it that way, like i did on my previous FC, but is there a way to do it with the glow switch? or can you only use a 2 prong regular switch?

 

If you use a relay, you can make the switch glow. Connect the NC contacts of the relay in series with the fuel pump power wire (blue as posted above, not black/red as I mentioned). Now simply connect up your glow switch so that it's 12V input goes to a 12V source, it's ground goes to...well, ground....and it's output goes to one side of the relay coil. Ground the other side of the relay coil.

Now, when you flip the swtich "on", it will glow and cut off the fuel pump. When you flick the switch "off", it will de-luminate (is that a word?), the relay will once again close, and you will have fuel. If you place the relay near the fuel pump, you avoid the voltage drop....

But that sounds like a lot of work to make a switch glow.

 

cool thanks a lot aaron, will it really effect the voltage that much? i wouldnt think so... i guess it ist really that important to make it glow/use a glowing one, but i already bought it so i'll see if i can make it work.

 

Not really alot, but it certainly can't help as the FC is prone to electrical disruptions...Any voltage sag would be amplified by the long wiring runs...Even a few ohms would make a major difference.