Bracket Car Wiring Help

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demon322

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Wiring my Demon race car from scratch and would love some feedback or advice on my plans. I’m on a bit of a time crunch here so I need to get it right the first time if possible. Hoping a good plan will save some time and I can get right to work when I get it back from paint. I bought a painless universal kit (50001) and want to use the switch panel that came with the car and MSD 6AL ignition.

The battery is rear mounted so I was thinking power for the harness from the starter post (through the MIDI fuse as listed here) and the MSD box will also need power. Another question is to run the stock NSS in the transmission or the one in the B&M shifter and also if I will need to run a Chrysler style starter relay for NSS function.

Things that need powered are radiator fan, water pump, transmission cooler fan, fuel pump, water pump, line lock, and interior fan for the driver. I am working on a diagram to lay all this out before I get started but would appreciate any input.

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@crackedback has a great way to wire in a trunk mounted battery. I tagged him so he should chime in.
 
I use the B&M nss and a Ford style relay.

The nss wires in the car makes it easier if you have problem.

I like the Ford relay as the studs are a great place to pick up power.
 
The main thing is a mega fuse of 200 amps right at the battery + terminal and another 50 to 100 amp mega fuse at the alternater output lug. That way in a crash a pinched wire can't continue to arc, possibly re lighting any fire or starting one. Then every stepdown in wire size needs fuse protection at the fuse panel or at a split if for some reason that is done.
Also every connection should be soldered, then covered with a heat shrink tube to prevent flex and wire breakage. It might seem like overkill. But my wiring is over twenty years old and i have never had a failure anywhere in my 8 sec bracket car.
 
One thing I didn't do and I wish I did was to use a specific color wire for each circuit. Maybe next time.
 
Crackedback diagram in this post: questions about battery disconnect wiring

MSD heavy red should be connected to the battery/alternator power circuit.
MSD light red is the on/off. It should be connected to the key or switch on run.
If using a one wire alternator (no external field power) it could be also be tied to the kill switch.

Re: colored wires. Wire barn is a pretty good source. Some marine supply centers sell by the foot. That's another good option.
 
guessing that "from scratch" means all the factory wiring is gone? curious what you're using for a fuse block and did you get a kit or going to roll your own
Wiring Depot is another good source
 
guessing that "from scratch" means all the factory wiring is gone? curious what you're using for a fuse block and did you get a kit or going to roll your own
Wiring Depot is another good source

Sorry. I left out some important information. The fuse box and all factory wiring is long gone. So I’m hoping that painless kit takes the place of that what little I have that needs power. Also I don’t run an alternator so that is one less option to hook into for power. And I forgot to mention on my ‘needs power’ list front park and rear tail lights. Won’t be running headlights or brake lights.

Thanks for all the feedback so far!
 
Pretty simple figure out if you want the starter battery cable hot all the time or not.

If you want it cold when not starting and depending on amp load, run a 2-6ga single cable forward from the cutoff switch feeding the fusebox/switch box... DONE! Branch anything else off the fusebox or buss point up front. No alternator makes it simple.

I hook MSD's up all the time on a buss point that has a well sized feed cable. Never an issue.

If that switch box has relays in it, great. If not, I'd set up a relay gang to run all those components and keep the load away from the toggles.
 
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Pretty simple figure out if you want the starter battery cable hot all the time or not.

If you want it cold when not starting and depending on amp load, run a 2-6ga single cable forward from the cutoff switch feeding the fusebox/switch box... DONE! Branch anything else off the fusebox or buss point up front. No alternator makes it simple.

I hook MSD's up all the time on a buss point that has a well sized feed cable. Never an issue.

If that switch box has relays in it, great. If not, I'd set up a relay gang to run all those components and keep the load away from the toggles.

I assumed the starter battery cable would be hot all the time that the master cutoff switch is on unless that’s not a good way to do it.

So I was thinking starter hot to this 100amp MIDI setup that came with the painless kit and then the other side to both the relay box and the MSD box?

Most circuits are relayed as noted in the attachment above but not all. Here is the relay layout and the supplied fuse.

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Another question when I get to that part of the job - what about running more than one thing on one circuit? For example running both the radiator fan and cooler fan to the same switch? Or I think someone suggested to me water pump and radiator fan on one switch and cooler can on another? I may have that wrong though.

Thanks.
 
Just a quick sketch to see if I’m on the right track. Feel free to point out any mistakes I’ve made. A few questions I’ve thought of.

When using the ford solenoid, does that eliminate the need for the Chrysler style relay or no? Where will the NSS wire go? Also what about the small post on the starter?

Thanks all.

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You most certainly can use a Ford solenoid. The nns wire goes to one of the small posts. The other small post is the feed from the start button
 
That seems simple enough. What about the small post on starter? Did I have my diagram wrong? Is it wire from the battery to the big post on starter and then little post of starter to ford solenoid? I like the simplicity of this style - I will just have to find a place to mount it on the firewall.

This was her today in the body shop. I’m told not long now!

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The small post on the starter get the feed from the solenid. Thats one of the the big posts. The other big post is cable from the battery and on that same post is the big cable to the starter. Your diagram is wrong.
 
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Thanks! That’s why I’m doing this. I knew that diagram was just a ‘first draft’ but I needed to start somewhere as I have trouble visualizing, especially wiring.

I’ll work on a new one. So cable from rear of car to one side of solenoid. From that same side a cable to big post of starter. Cable from other side of solenoid to small post on starter?

If I have that part correct I assume I can still use the side of the solenoid with the battery cable to power the painless box and msd box? Or am I missing a step there.
 
Thanks! That’s why I’m doing this. I knew that diagram was just a ‘first draft’ but I needed to start somewhere as I have trouble visualizing, especially wiring.

I’ll work on a new one. So cable from rear of car to one side of solenoid. From that same side a cable to big post of starter. Cable from other side of solenoid to small post on starter?

If I have that part correct I assume I can still use the side of the solenoid with the battery cable to power the painless box and msd box? Or am I missing a step there.

Yes and yes! You can pick up power on the battery cable side.
 
JMO, there is no good reason to run a ford solenoid if running the starter load through the cut off switch.
 
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