Cut-Off Switch Wiring

[nightrain]

I could use a little advice on wiring up a cut-off switch in conjunction with Casper's "volt booster" for the fuel pump. I got tech'd out at the track last Friday as my cut-off switch didn't shut the car off (first time in 8 years they checked it). It certainly wouldn't start again, but the alternator is still powering something. I'm wondering if anyone has a schematic they can share that would include how to wire up the switch with the volt booster included. Or let me know if it doesn't make a difference and perhaps I have the alternator feedback line wired up wrong. Getting limited to 11.50 or slower and hitting the brakes on the top end with a pit full of Mustangs was an ego buster...

Thanks!

 

[pacecarta]

run the alt power out wire back to the battery positive post ( 6 awg ) , or to the switch post that goes to battery + post .. same thing
I run main pump power (to the relay by tank ) with a 30A inline fuse (or a fuse link) off the switch post that runs to starter ..cuts out a lot of wire and insures the kill kills the pump
when you kill the switch the pump is cut off from battery and without the power to starter fusible links the alternator wont have a field and will stop putting out voltage

with a chip the orange mem wire should be run to battery and attached to the battery + terminal (or back of alternator ..same thing )

 

[nightrain]

Thanks! That sounds plausible. I'll give it a shot.

 

[GNVenom]

http://www.installationinstructions.com/FYI/battery-trunkmount.pdf

 

[Nick Micale]

John, what switch brand or type has the dual contacts for this application?

 

[GNVenom]

http://www.summitracing.com/parts/tay-1033/overview/

Here is one that Summit sells, with the interlock switch. Look for any four terminal battery disconnect, which has the interlock.

 

[nightrain]

Hey I appreciate the help! Still a bit puzzled, though. The schematic John sent indicates an "F" terminal on the alternator is to be used (I had that schematic already). But, my GN shop manual shows 4 terminals on the back of the alternator with only one being used; brown wire marked as "L" terminal. S, P, L, P are the 4 terminals.

I'd like to be able to cut power to the coil pack so the car shuts down instantly upon turning the switch (I have the one from Summit linked in John's second post). The fuel pump also needs to shut off as that's the important part. I think the Tech guys at the track are not going to want to wait for the fuel rail to run dry if only the pump is cut off when the switch is turned. In the few seconds it takes for the rail to run dry, they'll claim the switch isn't cutting power as it should (or how they want...these guys up here are...meticulous).

Would taking the ground from the coil pack and the ground off the fuel pump and run both through the secondary switch terminals work? The secondary (small) terminals are not connected to the battery power circuit, so I can switch anything through the secondary terminals. Just wondering if cutting the grounds while the car is running will shut it down.

Thanks!

 

[pacecarta]

the way i posted when switched off there is no power to anything ...the car will shut off instantly