Question: NHRA 9.99 or faster Battery Cutoff switch

[smkndmax05]

Hey guys,
I did a little searching but didn't find a whole lot. NHRA I guess requires a battery cutoff switch at the rear of the truck for faster than 9.99. I was just going to break the ground curcuit, but read it didn't work correctly. Anyone have some pictures or anything that actually works. I'm assuming Ihado Rob has it figured out by now. Thanks Matt

 

[MAXX IT OUT]

NHRA wants a positive disconnect for some reason, where as most other motor sports require a negative disconnect. Either way works but it has to be wired in property. I just finished doing mine, it's not all the way to the back, but still took a fair bit of wire to do. I wired the starter and fuse block to the dead side of the switch and the alternative and battery to the other, the switch was a flaming river big disconnect switch.

 

[A. Stock Lbz]

It is required because if your in a wreck it needs to shut the truck off. It won't pass tech if it doesn't shut the truck down in the off position. I would also run a separate line back to the switch for the alternator.

 

[bcdeutsch731]

I run mine on the ground side and never once have failed safety in the last 3 years. It will kill the engine on the ground side.

This is the one I used

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

 

[lts1ow]

You can always run a big ass solenoid switch up front to save the hassle of running 1/0 all the way to the rear.

My grievance on my car with the switch is the alt line will always be hot, one day I will figure that out

 

[A. Stock Lbz]

You can always run a big ass solenoid switch up front to save the hassle of running 1/0 all the way to the rear.

My grievance on my car with the switch is the alt line will always be hot, one day I will figure that out

Same here. Somebody needs to make a switch to kill power to the alternator also

 

[smkndmax05]

Thanks for the input guys, I'm talking to Brett now that I text the right number. :thumb:

 

[MAXX IT OUT]

Same here. Somebody needs to make a switch to kill power to the alternator also

You just have to connect the alternator to the battery side of the switch and it will work, same goes for the solenoid. At least with the solenoid you can mount it up front so you have short battery cables. The all you have to do is run some 16 gauge to the back with a smaller switch to kill the 12v signal to the Solenoid.

 

[lts1ow]

You just have to connect the alternator to the battery side of the switch and it will work, same goes for the solenoid. At least with the solenoid you can mount it up front so you have short battery cables. The all you have to do is run some 16 gauge to the back with a smaller switch to kill the 12v signal to the Solenoid.

Alternator on battery side means that switch off, that line will still be hot.

Unless you get a fancy switch that can do two isolated switched lines?

 

[GM_Guy]

Alternator on battery side means that switch off, that line will still be hot.



Unless you get a fancy switch that can do two isolated switched lines?

The alternator will be connected to the battery but disconnected from all electrical components.

 

[lts1ow]

The alternator will be connected to the battery but disconnected from all electrical components.

Yup, but the battery is still connected to chassis and you have a nice long run of a hot lead to potential spark against chassis etc etc if you get a bad wreck.

Not saying its wrong, or right, just one of my grievances with how I wired my car is all.

 

[LBZ]

NHRA wants a positive disconnect for some reason, where as most other motor sports require a negative disconnect. Either way works but it has to be wired in property. I just finished doing mine, it's not all the way to the back, but still took a fair bit of wire to do. I wired the starter and fuse block to the dead side of the switch and the alternative and battery to the other, the switch was a flaming river big disconnect switch.

Hopefully your flaming river doesn't go up in flames lol.

Last company I worked for had a pile of these on their heavy trucks and equipment and we had a high failure rate. Which is sad because they are a very nice looking disconnect. And expensive. Best ones I've found and used for cost and durability are the Cole Hersey ones.

I'd use this one for race or pulling

http://www.partdeal.com/cole-hersee...GaStwSRcwz9pwnNDiAU4AVOlBGEReb7ZFIaApT28P8HAQ

Or this one just for a simple on/off

http://www.partdeal.com/cole-hersee...yIP_vJuPTq_IS7oZfJ5wXEDq7Mtf4km76caAkIW8P8HAQ

 

[MAXX IT OUT]

Yup, but the battery is still connected to chassis and you have a nice long run of a hot lead to potential spark against chassis etc etc if you get a bad wreck.

Not saying its wrong, or right, just one of my grievances with how I wired my car is all.

On one of my old trucks I broke the positive battery cable going threw a mud and didn't realize it, but the truck still ran fine off the alternator. Thats why I wired mine up the way I did. A Ground discount works fine, but in my mind is is easier for a piece of metal to ground out to make the switch worthless and it keeps your fuel pump feeding a fire or something like that verse a piece of metal that creates a just creates a short.

Hopefully your flaming river doesn't go up in flames lol.

Last company I worked for had a pile of these on their heavy trucks and equipment and we had a high failure rate. Which is sad because they are a very nice looking disconnect. And expensive. Best ones I've found and used for cost and durability are the Cole Hersey ones.

Don't tell me that, what was the failure? To much use or crappy build quality?

 

[GM_Guy]

Yup, but the battery is still connected to chassis and you have a nice long run of a hot lead to potential spark against chassis etc etc if you get a bad wreck.



Not saying its wrong, or right, just one of my grievances with how I wired my car is all.

Gotcha, yeah I suppose it depends if you just want to pass tech or go the extra step for safety.


Wish I didn't have to relocate my battery.. A kill switch is really not ideal on a daily driven truck, I can only imagine how much it'll get messed with.

 

[smkndmax05]

I will be working on the wiring this evening. I'll keep everyone posted. Thanks for all the replies!!


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[TheBac]

I thought the switch had to be push-pull?

 

[lts1ow]

I thought the switch had to be push-pull?

If its that style, it just needs to be push to be off.

 

[smkndmax05]

So let's make the rules confusing as we can None of them say the same thing. Lol



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[LBZ]

On one of my old trucks I broke the positive battery cable going threw a mud and didn't realize it, but the truck still ran fine off the alternator. Thats why I wired mine up the way I did. A Ground discount works fine, but in my mind is is easier for a piece of metal to ground out to make the switch worthless and it keeps your fuel pump feeding a fire or something like that verse a piece of metal that creates a just creates a short.


Don't tell me that, what was the failure? To much use or crappy build quality?

They would either get too hot when cranking to start when it was cold or they would seize up and get real tight to turn, and we had two just short out and catch fire going down the road.

After the second one caught fire we found out from Western Star that they wouldn't warranty any trucks that had electrical issues if we had these installed because of all the issues they had been seeing so they spent a few g and replaced them all in everything.

Not sure if there was a batch of Chinese knockoffs around or if they switched who they had build them or what. I remember 20 years ago they were tits. Now not so much I guess.

 

[Dan@PPE]

I thought this only pertained if the battery was relocated to a location other than stock, did it change?