Author Topic: Battery Cut-Off/Kill Switch  (Read 2936 times)

Offline lake_harley

  • Sr. Member
  • ****
  • Posts: 262
    • View Profile
  • Your Best Time: 7.06 @99.58 - 1/8 mi.
  • Your Engine: Carbureted, gas mild 305 Chevy
  • Your Track: Jeffers Motorsports Park - Sikeston, MO
  • Your Vehicle: 145" FED
  • General Location: SE Missouri
Battery Cut-Off/Kill Switch
« on: January 07, 2023, 08:00:59 PM »
I hope to be wiring my FED soon and want to do it right. I've read some on battery cut offs and kill switches and the required/suggested locations for either or both, but remain a bit confused (nothing new there).

I'll be running a GM HEI battery powered distributor, so killing the power to it will kill the engine. Does there need to be a main battery cable run all the way to the rear of the car and then back up to power the starter to disable the entire electrical system? Seems like all of that "hot" battery cable from in front of the engine, where the battery is located, to the back for a main disconnect/emergency kill switch is a danger in itself.

I plan to have my single wire alternator alternator wire going directly to the battery positive. If all of the power for everything else in the car goes to the back of the car with a "Push Off" main switch and goes to a junction block to power the ignition, start button, fuel pump, water pump and taillight is that OK? Pushing it "Off" would kill all power (and the engine) other than the alternator wire and the positive battery cable to the main starter lug. That main power feed (maybe 10 Ga.?) going to the "Kill" switch could be fused in the front so power would be interrupted in case it were to be shorted out on the run to the back of the car. I'm guessing it would need to run through a section of tubing where it passes the flywheel and torque converter.

I hope my rambling isn't too random to understand. Suggestions, or better yet, a wiring diagram would be helpful and appreciated. I'm not totally illiterate when it comes to electric circuits but want to be in line with what's appropriate for a mild, bracket race FED.

As always, thanks, in advance!

Lynn
« Last Edit: January 07, 2023, 08:04:30 PM by lake_harley »

Offline JEFF/21C

  • Full Member
  • ***
  • Posts: 122
    • View Profile
  • Your Best Time: N/A
  • Your Engine: 306 SBC INJECTED ALKY
  • Your Track: NONE
  • Your Vehicle: 23 T ALTERED
  • General Location: eastern canada
Re: Battery Cut-Off/Kill Switch
« Reply #1 on: January 08, 2023, 05:57:44 AM »
we ran a push-pull cable to the back and the switch close to the battery

Offline lake_harley

  • Sr. Member
  • ****
  • Posts: 262
    • View Profile
  • Your Best Time: 7.06 @99.58 - 1/8 mi.
  • Your Engine: Carbureted, gas mild 305 Chevy
  • Your Track: Jeffers Motorsports Park - Sikeston, MO
  • Your Vehicle: 145" FED
  • General Location: SE Missouri
Re: Battery Cut-Off/Kill Switch
« Reply #2 on: January 08, 2023, 08:23:39 AM »
Thanks for the suggestion. I have looked into that option as well so the cut-off would be near the battery and the main battery positive cable would be as short as possible. Since I'm using a stock length Powerglide I'd guess the cable would have to be about 80" long to reach from the left rear corner of the chassis to near the battery, since the battery is just ahead of the fuel tank which is just in front of the engine. Some of the remote battery cut-offs I've seen use a rod, but with the distance and obstacles to clear along the way it would have to be a cable.

I can't help but ask though, is my plan just a bad plan in general (if it made any sense as written), or one that wouldn't pass muster in a tech inspection?

Lynn
« Last Edit: January 08, 2023, 09:33:47 AM by lake_harley »

Offline JEFF/21C

  • Full Member
  • ***
  • Posts: 122
    • View Profile
  • Your Best Time: N/A
  • Your Engine: 306 SBC INJECTED ALKY
  • Your Track: NONE
  • Your Vehicle: 23 T ALTERED
  • General Location: eastern canada
Re: Battery Cut-Off/Kill Switch
« Reply #3 on: January 08, 2023, 09:49:13 AM »
we had the pull knob located on a red mounting plate on the right rear part of the cage about the height of the tire the cable just followed the top frame tube

Offline lake_harley

  • Sr. Member
  • ****
  • Posts: 262
    • View Profile
  • Your Best Time: 7.06 @99.58 - 1/8 mi.
  • Your Engine: Carbureted, gas mild 305 Chevy
  • Your Track: Jeffers Motorsports Park - Sikeston, MO
  • Your Vehicle: 145" FED
  • General Location: SE Missouri
Re: Battery Cut-Off/Kill Switch
« Reply #4 on: January 09, 2023, 05:48:05 AM »
Thanks again. I guess a push-pull cable would be as easy to route as the extra wiring I had in mind and probably simpler in the end. Typically the rear shut off should be "push off" to kill the power for easier operation in the case of it being needed in an emergency, correct?

Lynn

Offline THE FRENCHTOWN FLYER

  • Sr. Member
  • ****
  • Posts: 360
    • View Profile
  • Your Best Time: 8.28@168 door; 9.00@147 6-cyl alt; 8.53@160 RED
  • Your Engine: 300 Ford six NA w/ crossflow and prod. heads
  • Your Track: Milan, Thompson
  • Your Vehicle: (3) Advanced Chassis altered , The Last Logghe altered, '30 RPU
  • General Location: North Coast
Re: Battery Cut-Off/Kill Switch
« Reply #5 on: January 09, 2023, 09:18:43 AM »
Yes, tech requires the engine cutoff switch be "push to disconnect" in the case of a push/pull switch. You can orient the switch or the twist-off lever to get this action. I have had to put a stud in the end of a switch that had a thumb lever to attach the rod. Some levers are hollow. In that case in addition to tapping the lever for the stud I filled the hollow in the switch lever with JB Weld for strength.

BTW, these switches do not last forever. I have had to replace one that was giving an intermittend bad connection. Maybe using isolator grommets would have prolonged it's life?

Offline lake_harley

  • Sr. Member
  • ****
  • Posts: 262
    • View Profile
  • Your Best Time: 7.06 @99.58 - 1/8 mi.
  • Your Engine: Carbureted, gas mild 305 Chevy
  • Your Track: Jeffers Motorsports Park - Sikeston, MO
  • Your Vehicle: 145" FED
  • General Location: SE Missouri
Re: Battery Cut-Off/Kill Switch
« Reply #6 on: January 09, 2023, 06:53:36 PM »
Thanks for the clarification and suggestion. This afternoon I abandoned my thoughts of doing some sort of electrically switched cut off and ordered a push/pull cable. I already have a manual battery cut off on hand and after thoughts of using the hollow handle to attach a cable, I decided to fabricate/machine a different steel or aluminum handle with a bit extra length for leverage to lessen the push/pull load on the cable itself.

I appreciate all of you who have offered sound advice when I'm stumped. This FED stuff is all new to me. I am thoroughly enjoying the build process and look forward to the car moving under it's own power!

Lynn
« Last Edit: January 09, 2023, 06:55:32 PM by lake_harley »

Offline slingshot383

  • Full Member
  • ***
  • Posts: 143
    • View Profile
  • Your Best Time: 1/4 mi. 7.95 @ 168
  • Your Engine: Chrysler, alcohol, 528 cu.in.
  • Your Track: Gateway Motorsports Park (the Swamp)
  • Your Vehicle: Undercover Chassis 23T altered
Re: Battery Cut-Off/Kill Switch
« Reply #7 on: January 17, 2023, 04:11:52 PM »
The other reason for the cutoff switch up by the battery and using a cable is weight, and simplicity.
Undercover 23T Altered, big block Mopar
Member of the Torque and Recoil Club

Offline THE FRENCHTOWN FLYER

  • Sr. Member
  • ****
  • Posts: 360
    • View Profile
  • Your Best Time: 8.28@168 door; 9.00@147 6-cyl alt; 8.53@160 RED
  • Your Engine: 300 Ford six NA w/ crossflow and prod. heads
  • Your Track: Milan, Thompson
  • Your Vehicle: (3) Advanced Chassis altered , The Last Logghe altered, '30 RPU
  • General Location: North Coast
Re: Battery Cut-Off/Kill Switch
« Reply #8 on: January 17, 2023, 06:17:05 PM »
Thanks for the clarification and suggestion. This afternoon I abandoned my thoughts of doing some sort of electrically switched cut off and ordered a push/pull cable. I already have a manual battery cut off on hand and after thoughts of using the hollow handle to attach a cable, I decided to fabricate/machine a different steel or aluminum handle with a bit extra length for leverage to lessen the push/pull load on the cable itself.

I appreciate all of you who have offered sound advice when I'm stumped. This FED stuff is all new to me. I am thoroughly enjoying the build process and look forward to the car moving under it's own power!

Lynn
We are rooting for you.

Offline Curly1

  • Sr. Member
  • ****
  • Posts: 260
    • View Profile
    • AireTex Compressors
  • Your Best Time: 7.95 @ 167 1/4 mile
  • Your Track: Texas Motorplex
  • Your Vehicle: 125" Altered
Re: Battery Cut-Off/Kill Switch
« Reply #9 on: May 04, 2023, 05:32:02 AM »
On my Altered I built I put the battery in the back with a push off mechanical shut off. Then the battery cable goes to electric solenoid for a master kill switch that I can kill all power from inside my car. I turn main power on when I pull it out of trailer and use the inside switch during the day.

Offline THE FRENCHTOWN FLYER

  • Sr. Member
  • ****
  • Posts: 360
    • View Profile
  • Your Best Time: 8.28@168 door; 9.00@147 6-cyl alt; 8.53@160 RED
  • Your Engine: 300 Ford six NA w/ crossflow and prod. heads
  • Your Track: Milan, Thompson
  • Your Vehicle: (3) Advanced Chassis altered , The Last Logghe altered, '30 RPU
  • General Location: North Coast
Re: Battery Cut-Off/Kill Switch
« Reply #10 on: May 05, 2023, 05:45:30 PM »
On my Altered I built I put the battery in the back with a push off mechanical shut off. Then the battery cable goes to electric solenoid for a master kill switch that I can kill all power from inside my car. I turn main power on when I pull it out of trailer and use the inside switch during the day.

I do exactly the same thing.

In one instance where I hit the wall, got knocked semi conscious, momentarily lost my vision, and spun around toward the starting line at a high rate of speed the inside switch kept a lot of people standing around the starting line from being hurt. Not to mention myself.

Offline wideopen231

  • Hero Member
  • *****
  • Posts: 1911
    • View Profile
  • Your Best Time: 1/8 3.70@ 198 1/4 5.78@245
  • Your Engine: Hemi 526 ci alcohol
  • Your Track: Piedmont
  • Your Vehicle: 225 CMC FED
  • General Location: NORTH CAROLINA
Re: Battery Cut-Off/Kill Switch
« Reply #11 on: May 05, 2023, 05:57:07 PM »
On my FEd I have a battery in nose, switch just in front of the engine, and push/pull will be at the rear if I get it hooked up.LOL I have got to do it  and will need a switch with terminal's for mag also,
Relecting obama is like shooting right foot because it did not hurt enough when you shot left foot