Which wire kills car via alternator wires

[Wings65288]

Trying to see if I'm thinking about this correctly. I have a trunk mounted battery and the track is requiring a manual kill switch on the back of the car.

So here's my plan, take the LT Green wire in the pics below and cut it, solder in 2 wires so I can extend the LT Green wire all the way to the back of my car. Connect the 2 wires into a kill switch. And when the switch is OPENED it will basically open up the LT Green wire.

So basically just to be SURE if one were to cut that LT Green wire the car would stop running correct?

Here's the pics

 

[2000GTSTANG]

If you cut the field wire to the alternator, the car will still run on the battery until it drains.

I would use a kill switch that cuts power from the battery and the alternator field wire as well, to protect the alternator.

 

[Wings65288]

Ok is the field wire that LT Green wire?

 

[Wings65288]

Oh u mean FEED wire correct?

 

[2000GTSTANG]

Field wire is the wire that energizes the field circuit inside the alternator, so it can create power. Without it, the alternator just spins and does nothing.

I cannot help you with what wire is correct or not. I believe you have the right one.

 

[Wings65288]

Sweet thank you

 

[Wings65288]

So it looks like it's a yellow/white wire. As long as I can open that AND the positive side of the battery the car should shut off.

Here's the switch I'll probably use. It's got 2 connections for the battery rated for 175 amps and also 2 connections for the exciter wire for the alternator rated at 20 amps.
https://m.littelfuse.com/~/media/co...-double-pole-battery-disconnect-2d-prints.pdf

 

[DSG2003Mach1]

do the rules say how it has to be cut off? I thought some of them specified if it had to be a ground kill or not

 

[Wings65288]

Yeah it says on the positive side of the battery. Can't do the ground side.

 

[03' White Snake]

I ran 2 new power wires from my switch, 1 to the fuse box and 1 to the alternator. The fuse box wire is on the open switch side. The cutoff switch kills power to the fuse box (shuts the car off). The other power wire from the alternator goes to the always hot side of the switch and battery. So when the car is shut off, the alternator is still spinning making power for a second or so, you want the car to shut off immediately but still have a path for power in the alternator back to the battery. This is the proper way to wire it.

I ran a 2ga to the fuse box and 4ga to the alternator. You will need to remove the factory wire from fuse box to alternator too. Need to re-attach the white/red sense wire too so the battery light is not on all the time.

 

[Wings65288]

How did you get that nut off the fuse box? Mine has been mangled by the previous owner. Does this HAVE to be removed?

 

[Wings65288]

Well now that I think about it I can cut wire that's CURRENTLY on that fuse box and just extend back to the killswitch

 

[Wings65288]

Actually can anyone answer me this. If I cut the ENTIRE positive side of the battery AND also the field wire to the alternator will this kill the car?

 

[Wings65288]

Well I can confirm this will work. Cut the field wire and disconnect the battery and the car will immediately shut off and all power is dead of course.

 

[Wings65288]

So the significance about this is for those with a trunk mounted battery that have to put an external killswitch on your car this will immediately kill the car and the power. So basically you're going to want this switch here:

And basically you wire the small alternator field wire in between the 2 very small poles (rated for 20 amps which is plenty) and wire in the positive side of the battery on ONE end of the big poles and then exit out the other big pole to your alternator. Just make sure you've COMPLETELY "cut" the positive side of the battery when you open up the switch.

 

[03' White Snake]

This is the switch I ran thru the rear tail light.... works great.

https://www.summitracing.com/parts/fla-fr1003-2

The power wire and solid state fuse on the rear of the battery box is for my fuel system, so ignore that.