Correct way to wire battery cutoff switch.

[DSM Jeff]

Well its finally nice and boss let me out 2 hours early with pay!.

Anyway, heres how I did my battery switch on my 90. New charge back wire from the alternator runs under the radiator (zip tied to the wire harness thats there and is covered with wire loom) I have an 80amp circut breaker mounted near the intake (plenty of room). I do not have pics of this part of my system. Then charge back wire runs through the firewall (used a rubber grommet as well) down the passenger side of the car to the rear.

***NOTE*** I disconnected the oringal chargeback wire from the alt. It runs to the 80amp fuse in the fuse box. This fuse is screwed in with a 10mm bolt. The wiring was removed, keep the fuse and bolt for later.

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Heres my battery and battery box. (don't mind that is not hooked up or bolted in, car has no engine at the moment) the top wire is the ground(bro robbed my terminal) On the positive terminal, the top red wire is the charge back from the alt. The lower red wire goes to the switch.

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The switch (in the off position) is mounted to the body with an aluminum plate as a spacer. I found this allowed the switch to function better. The switch is made by Flamming River and has an extension rod. The lock cylinder was removed and the hole opened up with a dremel about an 1/8" on one side so the rod can move freely. The wire comes from the battery to a 100amp fuse (not sure if this is needed but I figure better be safe and 100amp is all they had, i wanted 80) Then from the fuse to the switch. On the other side of the switch the fuel pump rewire goes right to my fuel pump with a inline fuse in that as well. The main power wire from the other side of the switch goes back through the body of the car.

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Shot of the rod coming out of the key hole in the car. When I'm not going to the track I can unscrew the rod and cover the hole from the inside with duct tape to keep water out. Call me ghetto.

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Yes, I have some rust, subframe is coming out for bushings and paint. The car has been sitting for a year and gets driven in the winter and goes to the track every now and then.

The wire comes back through the firewall (another grommet) to this distribution block. The red wire on the right is the power feed. The black wire coming from the bottom is the starter power wire. (note; the main ground is near that one) The white wire coming out of the top covered in wire loom goes to the fuse box on the side that the old alternator charge back wire ran to. Lastly the stock fuse box that mounted on the battery was removed and the wires run into the block with stock size fuses.

***THOSE WITH 92-94 CARS***
You can do the same thing using a different switch. Get a switch that has a silver knob on it. Its a "turn off" switch. Remove your right rear reverse lens by removing the black side cover on the license plate side. Remove the 2 screws and pull the light towards the license plate (its kinda hard to do because there are 2 tabs that go into plastic inserts to hold it) You can bolt the switch in and simply reinstall the lens and light to keep things looking stock. It fits, I've done it. When you get to the track, unscrew the light, slap a 'shut off' sticker there and have fun.

I've done this set up on 2 cars. It kills all power to the car and fuel pump. Not sure if this is the best way but it works.

Good Luck.

 

[RipperXX]

I think I might end up just getting a light weight "racing" battery, seeing as I likely added 10lb from relocating it.

 

[DSM Jeff]

I think I might end up just getting a light weight "racing" battery, seeing as I likely added 10lb from relocating it.

I don't think theres a whole lot of weight in my wiring. I love having an open engine bay reguardless. I also drive my car daily in the winter so one of those small batteries just isn't going to do in cold weather. And those oddessey batteries or any other small batteries, I hope you buy a maintainer because I've seen a lot go bad.

 

[RipperXX]

Well it would just be for track use. As I stated earlier I am NOT drilling any holes or cutting my rear bumper cause some damn NHRA rule book says I have to have a switch back there even though my car is maybe a 12sec car. I relocated the battery to help with weight distrobution not because I need more weight in the rear to launch a 1000hp car.

So it sucks but I will have to go from one to the other... Seems the only way I can make a few pass's at the track to see what my car even does.

 

[DSM Jeff]

Well it would just be for track use. As I stated earlier I am NOT drilling any holes or cutting my rear bumper cause some damn NHRA rule book says I have to have a switch back there even though my car is maybe a 12sec car. I relocated the battery to help with weight distrobution not because I need more weight in the rear to launch a 1000hp car.

So it sucks but I will have to go from one to the other... Seems the only way I can make a few pass's at the track to see what my car even does.

I understand. I've seen a few people who've put small batteries on the sub frame and gone to home depot to pick up some aluminum flat stock to make a bracket to secure the battery. If your car is not a daily though I'd get one of those battery maintainers to keep a charge on it. A few friends have had batteries die out because they are parked more then driven. I understand its not for everyone but hopefully my pics can help others figure things out.

 

[Syndicate13]

What exactly is the reason for the cutoff switch if you relocate the battery?

 

[RipperXX]

So a track official can shut your car down at the flip of a switch if you have a bad wreck and the engine is still running. However I still think it should be ET dependent or something.

 

[Syndicate13]

So a track official can shut your car down at the flip of a switch if you have a bad wreck and the engine is still running. However I still think it should be ET dependent or something.

Is it only required if you relocate the battery? I've never run in a sanctioned event and I don't plan to , I am just curious.

 

[DSM Jeff]

Is it only required if you relocate the battery? I've never run in a sanctioned event and I don't plan to , I am just curious.

Yes, the switch is needed if you relocate the battery. I've run at a small track on a test and tune and they asked where my switch was (didn't have one at the time) They told me I could run today since it was opening day. Said if I came back the next week they wouldn't let me run. Theres another small local track who've never asked. I know there are some rules about it somewhere. I just did it for less hassle. Had all the wiring and other components, just purchased a switch and put it together.

 

[95CarbonEclipse]

Why couldn't you just mount the kill switch directly behind your license plate? Just like in that other thread only put a spacer on the hinges so that when your plate is closed, it sit's approx. 3/4" away from being completely flush with your back bumper, it would kinda look like your license plate is floating just off of your bumper. Then just use the lowest profile switch that you can find. You really wouldn't even need hinges, only if you wanted easy access to it when your plate is still mounted on. Your plate would hide everything including the switch, and all the proper display information. Then, when you go to the track, take your plate off entirely and... Wha-La!! NHRA compliant. Here's a rough paintbrush diagram of what I'm talking about.

 

[this_tsi_8urV8]

Bringing it back!!!
Great idea, I was thinking of something like that. Has anyone done that?
I have a 2gb so it has a big black square to place the switch on. It will be a DD once I sell my DD in spring. Cant afford 2 cars that require premium fuel. The reason to relocate is to have more space and better weight distribution, but I do not want some punk kid or "import" hating a$$ person hitting the switch and erasing all my settings, specially on w/link. I dont carry my laptop everywhere.
Thanks.

 

[rrussell]

Why couldn't you just mount the kill switch directly behind your license plate? Just like in that other thread only put a spacer on the hinges so that when your plate is closed, it sit's approx. 3/4" away from being completely flush with your back bumper, it would kinda look like your license plate is floating just off of your bumper. Then just use the lowest profile switch that you can find. You really wouldn't even need hinges, only if you wanted easy access to it when your plate is still mounted on. Your plate would hide everything including the switch, and all the proper display information. Then, when you go to the track, take your plate off entirely and... Wha-La!! NHRA compliant. Here's a rough paintbrush diagram of what I'm talking about.

This what I did and I like it because it looks stock with the l-plate on.

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The little red and black wire is for my w/b its no longer there.

 

[this_tsi_8urV8]

Sweet! Great car you have there. I suppose w/b = wideband. That is what I'm talking about. Anyone have it on a 2g?

 

[slowgsr]

Sir, please make a change in the way you have relocated your battery, or anyone that has relocated it to the rear.

Do not use the chassis as ground. When you run your positive cable from the front to the rear, also run a ground cable from the front to the rear and ground it in the stock location, It does make a difference believe me.

Electrical grounding is very important, and electrical systems in cars are usually the most common overlooked part that is very vital to proper performance.

I don't to go into too much detail WHY this is so important, but please refer here for more info if you desire, or you can just disregard my post and continue to do what you are doing, but thats your choice.

Honda-Tech.com: Forced Induction: Reliability of stock temp gauge?

This was a topic i was involved in.

 

[this_tsi_8urV8]

By stock location, you mean where the battery's negative terminal was connected to?

 

[slowgsr]

To be honest with you, since im not that familiar with DSM's i couldn't tell you where i disconnect my chassis to battery negative terminal from, but it doesn't really matter how they did it from factory, the monitoring equipment from factory doesn't need to be as exact as what we want to measure with aftermarket, Ie. EGT's, WB02, actual coolant temp etc etc.. and proper grounding is essential to correct output readings of these devices, especially ones that work strictly off resistance based signals.

If anyones ever wired aftermarket accessories properly, the proper way IMO (not ways that just 'work') is to use a fusesable distribution block, and as well this should be done with ground as well (with ground directly from the battery), this way all your monitoring equipment has an excellent ground source.

However, the battery should be grounded to a clean spot on the framerail, which is probably where it is, and any spot on DSM's or any car for that matter that is a common ground spot (on honda's its the thermostat housing), should have a ground strap added from the common ground point to the battery negative to ensure a good ground.

Tuners can scratch their heads and wonder 'why did the engine detonate when my wb02 is telling me 12.5:1 AFR's and my timing is fine and everything else checks out' WB02's can be off as much as point if connected poorly.

I hate seeing hacked harnesses, and people who decide that any bolt that holds a piece of metal down is a good spot to wrap their ground wire around, and twisting the wires and connecting them with tape is another thing also.

I personally prefer high quality crimps, however they add up and the tools are expensive, high quality crimps add NO resistance, and i bet the wire will break before it pulls from the connector, at the VERY LEAST wires should be soldered and heatwrapped, unless they experience alot of movement, then crimping is the only way.

I hope i answered your question.. and maybe a bit more

 

[DirtyBirdRacing]

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Hi,

Sorry to bring this thread back from the dead but it is the best thread i have found so far on this topic.

Jeff, would you or anyone else have the particular part number for this Stinger fused distribution block? I would like to use the same one since it looks like a real good fit for my setup.

Also, since I am running the alternator charge wire back to the battery in the trunk I dont need the top white wire correct? I think that is what you said I just want to make sure.

Thanks a lot,
Bill

 

[twicks69]

Hi,

Sorry to bring this thread back from the dead but it is the best thread i have found so far on this topic.

Jeff, would you or anyone else have the particular part number for this Stinger fused distribution block? I would like to use the same one since it looks like a real good fit for my setup.

Also, since I am running the alternator charge wire back to the battery in the trunk I dont need the top white wire correct? I think that is what you said I just want to make sure.

Thanks a lot,
Bill

Bill,

The Stinger Part Number is SPD8124. You can Google "Stinger fused distribution block" and it comes up immediately. I found it as low as $23.00 at online stores, and the same price at Ebay.

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*If you are looking for similar verions, be sure to look for a fused distribution block with the following details:

--> 4-AGU fuse capacity (These fuses are common at any Radio Shack and go up to 80A)
--> 3x 4-gauge inputs
--> 4x 8-gauge outputs

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You can also find equivilant ones to this specific model:

*Sound Quest P/N: DFP411S $15.00

*You can also run MAXI fuses (Which are very accessable as well at auto parts stores).
-->MAXI Fuses are available in 20A, 30A, 35A, 40A, 50A, 60A, 70A, 80A, and 100A.

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Here is the same version, just for Maxi-fuses:
Stinger SPD8625 $31.00

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These are the cheapest and most accessable style of fuses used in high-end car audio fused distribution blocks. We also use:

*ANL (Waffle) fuses that are harder to get at places but are capable of 60A, 80A, 100A, 125A, 150A, 200A, 250A and 300A range.

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*MIDI fuses are in the 30A-150A range made for heavy gauge wire applications like 1/0-gauge. They aren't the easiest to get replacement fuses for.

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*Circuit Breakers ranging from 20A to 250A are not to be used in place of a fuse; instead they are meant to be used in conjunction with a fuse in-line to protect the electrical component.

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I hope that this more than answers your question, as well as gives you an idea of the availability and capacity of each style fuse so you can match it properly to your application.

Good luck,

 

[kevingst]

The factory grounds it directly to the firewall (chassis), so how would rewiring to the chassis or frame in the back be any different?

Any way... that's my car that was referenced in the other thread with the flip up license plate. I've actually wondered how that would go over at tech inspection. I'd done that batch of mods shortly after buying the car, drove it 70 miles, spun a rod bearing, and it's been in my garage since then. Just now getting it running again with my current mod list, hoping to get it on the road this weekend. Hope to get it to the track this year and see how it goes over at tech. If nothing else I'll take the plate off at the track, maybe cut the hole down a little further. To be honest though, I don't think my switch (uncovered) is any more hidden than some of them that blend in with the rest of the car.
Tim, why is it not ok to use just a circuit breaker on the pos wire? That's how I currently have it wired, guess I'm gonna be changing that soon, too.

 

[twicks69]

The factory grounds it directly to the firewall (chassis), so how would rewiring to the chassis or frame in the back be any different?

Any way... that's my car that was referenced in the other thread with the flip up license plate. I've actually wondered how that would go over at tech inspection. I'd done that batch of mods shortly after buying the car, drove it 70 miles, spun a rod bearing, and it's been in my garage since then. Just now getting it running again with my current mod list, hoping to get it on the road this weekend. Hope to get it to the track this year and see how it goes over at tech. If nothing else I'll take the plate off at the track, maybe cut the hole down a little further. To be honest though, I don't think my switch (uncovered) is any more hidden than some of them that blend in with the rest of the car.
Tim, why is it not ok to use just a circuit breaker on the pos wire? That's how I currently have it wired, guess I'm gonna be changing that soon, too.

You can, but I would still recommend having a fuse in-line to protect the electical components. If you are running your stock fuse block assembly in the car, you are fine. Circuit breakers are not meant to be the ONLY thing between the power and the component since they are much slower to react to an amperage exceedence. You want to have a faster-acting fuse between the circuit breaker and the component to protect from short term voltage spikes that can fry circuit boards, or pump motors, etc.


For example, when I did competition car audio many years back (1995-2000), I was running two Optima batteries with two circuit breakers using double 1/0-gauge wires for the entire setup, and 4-gauge to each amplifier. One circuit breaker was placed between the extra-high capacity alternator I was running and the battery, and the other circuit breaker was placed between the batteries' power wire and the capacitor (then line conditioner, then EQ, then amplifiers). Since the amplifiers I was running consumed up to around 220A-230A at the levels I was pushing them to, and were rated as high as 260A total, I wanted to place a safe limit on them so I didn't exceed the capacity of my alternator and exceed the amperage rating for my amps resulting in torching an amp. I had a 250A circuit breaker for the main power line to them. From that main power line, I had a in-line fusible distribution block very similar to the one you are interested in that used that used 4 MAXI fuses to a capacity of 240A with each one running to the respective amplifier, which still had its built-in emergancy fuses.

Essentially, it was a bit overkill, as I was double-fused for each amplifier, and had a main-line breaker setup for each direction on the battery (draw and charge sides).

It saved my butt several times where I would burn the maxi-fuse over extended high-draw durations, and protected the amplifier before it exceeded the higher Amperage fuse inside the amplifier. Or I would pop my circuit breaker from the alternator to the battery from a current spike from the alternator.

Long story short, a fuse can exceed its capacity for only so long before it blows. You want to make sure it is lower than the maximum allowable amperage that the component can take if it is in-line before the component. A circuit breaker is made for fast disconnection of the circuit during an electrical amperage spike (overcurrent). As well, once a circuit breaker has been tripped due to an overcurrent, it will progressively degrade every overcurrent it encounters and its amperage capacity (rating) will decrease. Use it as a safety, but not as your only fusible protection between an electrical component and the power source.

If you would like, here is an excellent resource for car audio, electical theory, and electrical wiring information. The site has been around for more than a decade, and I remember when I found it in 1998!

Basic Car Audio Electronics


The scroll menu on the right hand side will have ALOT of information that is usable in the racing field, as well as car audio, and basic and advanced electical applications, along with terminology and descriptions. Topics #14 and #15 cover Fuses and Circuit Breakers.


Thanks for reading my rambles.

 

[kevingst]

That's cool, I used to be big into car audio too and would use both (fuse blocks and c/b's) as well. I just wasn't sure why, in my case, a c/b wouldn't be ok. I'm still running my power wire to the 4 white wires in the fuse panel, so I guess I should be ok. Thanks for the answer.

 

[Redfwdsm]

From the NHRA rulebook:



You also have to wire the alternator directly to the battery to make everything work properly.

i wish i knew all this shit before i did my relocation kit cause now i gota add the cut off to run at the track and i dont want ppl to know im fast and if they see a cut off switch it ruins all my fun


well i guess it helps when i read everything cause i just saw that behind the plate thing but here's a question is the street tuned motorsports kit a complete kit to do the job?


STM DSM BATTERY RELOCATION KIT


thats what i orderd sorry i dont mean to jack the thread...

 

[twicks69]

i wish i knew all this shit before i did my relocation kit cause now i gota add the cut off to run at the track and i dont want ppl to know im fast and if they see a cut off switch it ruins all my fun


well i guess it helps when i read everything cause i just saw that behind the plate thing but here's a question is the street tuned motorsports kit a complete kit to do the job?


STM DSM BATTERY RELOCATION KIT


thats what i orderd sorry i dont mean to jack the thread...

Personally, that wire setup is a bit on the small side, and it doesn't look like STM understands electrical amperage capacity of a wire either.

4-gauge wire is only safely capable of capacitating 135A on a constant power wiring setup. As well, 8-gauge wire is only safe to 73A. The 200A circuit breakers are a bad choice with their wire kit utilizing 4-gauge and 8-gauge wire because you would torch the wire before popping the breaker. If you are going to use 4-gauge wire, use a 100A or 125A breaker instead. Even using a 150A breaker will be dangerous as it also exceeds the capacity of 4-gauge wire.

If this is a RACE ONLY setup, that utilizes no additional electrical power sources drawing from the stock alternator, then 4-gauge for the battery and alternator will work (BOTH WIRES being 4-gauge). I would not recommend 8-gauge whatsoever, and especially with the 200A circuit breakers.

Again, if you are going to use a stock alternator, and NO-AFTERMARKET-CAR-AUDIO, or high current draw accessories, then 4-gauge wire will be fine with the properly sized circuit breaker of 125A.

If you are going to use 200A circuit breakers, then you will need to use 1/0 or 0-gauge power wiring, and a 4-gauge ground wire, and it will definitely cost more than $80 for a wiring kit if done properly.

As well, do it the right way, and use firewall grommets or firewall isolators for power wires so you don't result in a short or electrical fire due to ground-out.

Here is a link to two styles of grommets that are quality parts:
Pegasus - Seals-It Firewall Grommet Seals

Here is a link for firewall isolators (bulkhead connectors):
Pegasus - Battery Cable Thru Panel Connector

Here are a few links for excellent quality cutoff switches that are NHRA legal for cars using alternators:
Pegasus - Master Battery Cutoff Switch with Alternator Protection
Pegasus - Longacre Battery & Alternator Disconnect Switch, no panel

Both cutoff switches utilize 3/8" ring terminals, and work with this type of insulating boot sized for 4-gauge wire:
Pegasus - Insulating Boot for Battery Cut-Off Switch Terminal


Here is a good table to understand power capacity of a specific gauge wire:
Copper Wire Table

If you are going to do it yourself, look for quality wiring with a very high strand count, and preferably zero-oxygen wiring or individually tinned wire strands. High-end car audio wiring and Mil-Spec wiring is capable of handling higher capacities. If you are going to use car audio wire, use a 4-gauge wire that has at least 1500-strands. For example, Stinger uses 4-gauge with 1666 strands of oxygen-free copper . Their 0-gauge utilizes 4284 strands of oxygen-free copper. You should be able to pick up Stinger wire for around $1.50 per foot for 4-gauge, and $4.00 per foot for 0-gauge.

As well, you want to look at its temperature capacity if being run through the engine bay by hot parts. If you are going to use 4-gauge, here is a link for a quality wire at $1.39 per foot and has a higher temperature range of -50 to 105-degrees Celsius (vs. Stinger 4-gauge temp range is -40 to 60 degrees C):

Pegasus - Battery Cable, 4 Gauge - Red

If this is a RACE-ONLY car with no audio system, you can run Mil-Spec wiring, but remember, it is UNSHIELDED and can cause signal noise issues if the wires are in contact with other wires, gauges, electrical source wires, etc.

UNSHIELDED WIRE<br>MIL-W-22759/16 from Aircraft Spruce

or

http://www.wicksaircraft.com/links/Wicks_Links/Electrical2007.pdf

or

Pegasus - Mil-Spec Tefzel-Insulated Electric Wire (MIL-W-22759/16)

It is the lightest stuff on the market, but you will NEED to use a proper Mil-Spec wire stripper to strip the wire without damaging the tin-coated wire. The wire casing is an extruded Tefzel PVC that can handle a continuous 105 degrees Celsius and a maximum temperature of 150 degrees Celsius. As well, the Mil-Spec wiring is the lightest stuff on the market at a fair price, and is $2.99 per foot for 4-gauge wire. It is still rated for 135A, and should use a 100A circuit breaker or a 70A in-line fuse to properly protect your copper wiring.

Here is the proper wire stripper:
Pegasus - Stripmaster Wire Stripper for MIL-W-22759/16 Wire (26-16ga)



Good luck with your project, and next time, please use proper spelling and punctuation. It makes it much easier to read what you are writing.

Thanks,