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Discussion Starter · #1 ·
I'm looking identify the switched power wire feeding my fuel pump relay on my 2000 Astro. I tried opening up the bottom of the fuse box to get my eyes on it but feel like I am about to shatter the box, does anyone know the color of the wire I'm looking for, or have any advice on opening up the fuse box? The idea is to locate that wire and install a kill switch since the city I live in no longer has police and a car gets stolen just about every night from a 4 block radius :D . No fuel= No tweaker driving my vehicle :clap:
 

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recently tackled some fuel pump issues and have my notes handy.
This is for a 1997 GMC Safari, it should give you a basic idea of what to look for

The fuel pump relay has 5 pins so 5 wires

red - Goes to jumper (Useless to for your application)
orange - Carries battery voltage [ from fuse to relay ] [ Hot at all times] (I guess this is what you would use)
black - Goes to chassis ground
grey - goes to fuel pump connector
green/white - goes to VCM

switched power wire? actually the GREY wire that goes to the fuel pump is "switched." I don't know anything about kill switches so just locate a wiring diagram for your vehicle's fuel pump relay.
 

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Discussion Starter · #3 ·
Okay! I ended up figuring it out. Heres a quick write up on how I wired a kill switch to my fuel pump.

KILLSWITCH ENGAGED!!

On my 2000 Astro the switched power (power on when keys on) is a green and white wire. Thats the wire I decided to interrupt, no fuel pump= No tweaker driving my van :clap: :clap:

I discovered this by pulling the fuel relay out of the fuse box and probing the terminals with a multi meter, looking for switched power (unbolt your fuse box and pull it out so you have more room to work).

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With only 4 wires it was easy to find.

Key off
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Key on
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I then tried to take the bottom of the fuse box off to see the wiring but I couldn't get the tabs to disengage, luckily I could see through a hole in the back and got my eyes on the terminal I was probing. Its green with a white stripe!

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Unfortunately there are two green/white wires in the wiring harness.

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No problem! With your multi meter set to the lowest OHM setting put one probe in the terminal and test each green/wire until you get a 0.5 reading, basically just checking for continuity, whichever wire gives you a reading close to that is the same green/white wire going to the terminal your probing.

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Awesome! Now the most difficult part, find a clever spot to stash your kill switch. This honestly took me the longest, don't forget to consider how you'll run the wire to the switch. Once you find a spot your happy with run two wires from your kill switch to the green/white wire you've identified as the fuel pump relay wire. Cut the green/white wire and connect your new wires.

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Test your switch out and don't forget to use it!!
 

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1998 LS AWD Forest Green metallic
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https://www.astrosafari.com/gallery/ima ... _id=104762
Thanks forthe color code info.

Here is my idea, in the ash try, but I have not hooked up that 'kill' switch yet. The other switch is to enable/disable charging to a very large battery to run amateur radio gear, sometimes a fridge, and other accessories.

Rod J
Issaquah, Wa
 

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Common Sense + Critical Thinking
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Highly recommend the GM Techline eSI minixp .ova in virtualbox(see links in sig) for your wiring diagram needs :)
 
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