30: Common
87: N/O
85: Coil
86: Coil

for some reason i can't think of which wire goes where for a fuel pump type kill switch. 30 goes to the "fuel pump" or whatever else i'm switching. 86 is ground. But what about the other ones, i'm stumped... Where do I get the other 2 12V wires from, and which one do i put the switch on?

 

87a one end of the cut fuel line
30 the other end of the cut fuel line

85 fused 12V+ ( found at your fuse box, or ign switch)
86 to your switch ( you switch sends 86 ground (-) when the F.K. is armed)

that should work.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nOOber &raquo;</TD></TR><TR><TD CLASS="quote">87a one end of the cut fuel line
30 the other end of the cut fuel line

85 fused 12V+ ( found at your fuse box, or ign switch)
86 to your switch ( you switch sends 86 ground (-) when the F.K. is armed)

that should work.
</TD></TR></TABLE>

Wouldn't i want to put one end of the cut fuel pump line to 87 and not 87a? b/c 87a is normally closed, meaning when the Relay isn't active (switch is off) there is always current running from 30 to 87a. That would defeat the whole purpose of the kill switch.

 

Technically either way will work. The problem with using 87 instead of 87a is that the relay will always have to be energized for the fuel pump to work. There will be a higher chance of the relay failing.

I would also recommend the layout given by nOOber. Just make sure your 12v+ source for 85 is constant.

 

Hmmm... now that you mention it,

perhaps Ignition would be a better trigger than +12 V for pin 85, that way the relay would only engergize during a start attempt/ theft.

It's your call, but I don't think I like the idea of the relay being energized for 8 or 10 hours at a time (at night for example)...

 

I'm still not getting what you're saying. For a power source, say i used something else to trigger the relay, such as the rear defrost, then a switch in line w/that. That way both have to be on for the relay to be energized. The relay would only get power when i'm in the car and push the defrost and flick the switch. Then if i had the fuel pump hooked up to 87, once the relay is powered up, then the fuel pump would get power. If i'm not getting something right, try to elaborate on your idea a little more, thanks.

 

Here's the deal:

If you want the relay energized while the car is running, connect 12v + constant or ignition to 86 and your switch to 85 (85 and 86 need to be opposite in polarity....it doesn't matter which goes to which). 87 would go to the fuel pump wire toward the fuse box and 30 would go toward the pump. When the ignition is on and kill switch is on, the fuel pump will receive power. When the ignition or switch is off, the fuel pump will not receive power.

If you want the relay energized while the car is off, connect 12v + constant to 86, kill switch to 85, fuel pump power (fuse side) to 87a and 30 toward the fuel pump. This way the fuel pump is always connected when the relay is at rest. Once the switch is turned "on", the fuel pump will be cut off. This scenario leaves you with the least risk of being stranded since the fuel pump is always connected unless the switch is turned "on."

 

ok, I'll try...

87a and 30 are connected when the relay is at rest.
when the realy is unenergized, the fuel pump works.

85 and 86 are the triggers to energize the relay.
when the relay is energized the fuel pump does not work.

you only want the relay energized when some is actually stealing the car.
To start / and stay running the Ignition must be on.
so 85 should be Ignition, your + trigger for the relay.

the other trigger (86) needs to be negative (-)
so, what ever you use ( an after market switch, or what ever) when its negative, and Ignition is ON the fuel pump wire is open, and does not work.


So, when you get out of your car you flip the switch to the ARM position ( so it shows neg. to 86)... now the relay stays unenergized, until you try and start the car (igntion ON)... at this point the fuel pump wont work.... until the switch is turned to the DISARM postion ( so there is no neg. going to 86).

 

nOOber....Yes you are correct. Your example supports the example I gave on if you want the relay energized while your driving.

ALL MOTOR LS....you can use whatever 12v + or ground signal you want provided that they energize or trigger the relay at the desired moment.