Ford Mustang Forums banner

1 - 20 of 35 Posts

·
Registered
Joined
·
743 Posts
Discussion Starter · #1 ·
First of all, this is my first posting, so hello.



I am getting ready to install my battery in the trunk, but I have a few questions I hope can be cleared up:
1. Is it safe to run the pos. cable throught the firewall and in the car to the trunk?
2. It sounds like Ill have to have a switch, but what is the advantage of using welding cable vs. battery cable from the alt. to the switch?
 

·
Registered
Joined
·
105 Posts
I am getting ready to install my battery in the trunk, but I have a few questions I hope can be cleared up:
1. Is it safe to run the pos. cable throught the firewall and in the car to the trunk?
2. It sounds like Ill have to have a switch, but what is the advantage of using welding cable vs. battery cable from the alt. to the switch?


The safest way to wire the starter cable is to mount a starter solenoid in the trunk next to the battery. Use it to switch power to the starter only when you are cranking the engine. In place of the fender mounted solenoid, use a junction stud block that runs back to the battery and to the alternator. Welding cable has much denser stranding, is more flexible and conductive.

Mitch
 

·
Registered
Joined
·
713 Posts
im not sure if you need to put the solenoid in the trunk,
its not nesscary and im too tired to think why.
use welding cable a must, i ran mine under the car.
and up through around the spare tire area.
you can add saftey components as time goes by.
i just added a 100amp from my battery to my cutoff, you can get those at a stereo shop
the list goes on, you will also need a relay to switch off the alternator when you cut off the battery. but that can wait.
 

·
Registered
Joined
·
2,999 Posts
you will also need a relay to switch off the alternator when you cut off the battery. but that can wait.
just use a summit battery disconect switch.....it kills the entire electrical system if you wire it correctly
 

·
Registered
Joined
·
713 Posts
as far as i know and im not postive, to be nhra legal or whatever
you need to cut off the alternator with the battery switch.
im not saying this is right, im just saying these are the rules
ive heard. ive never looked up the rules personally but i intend to
if i need to cover my azz. because i dont want to give false information, but it happens. also im sure nobody will ever check
but you never know.
 

·
Registered
Joined
·
1,253 Posts
To be NHRA legal you have to have a cutoff switch mounted in the rear of the car, easily accessed, and it has to be wired into the positive side of the circuit. It has to shut off ALL power to the car, even when running. If it's a push/pull type switch it must be push-off.

Click on the link below...it's all you need to know. :)

http://buffhomer.corral.net/custom.html
 

·
Registered
Joined
·
2,999 Posts
and if it is a turn on/off it needs to be labled off
 

·
Registered
Joined
·
713 Posts
what will happen if you remove the wire that senses voltage?
i did this and my eec got fried right afterwards doohhh
 

·
Registered
Joined
·
743 Posts
Discussion Starter · #10 ·
I checked out that diagram, Id actually seen it before. Would it be alright to ground it to the fraimrails right underneath the intended location? I saw in another thread that someone said in order to do that, you have to have subframe connectors and ground up front to the subframe as well. Is that true? That seems like alot of work just to ground a battery. Oh, nobody's said anything about the positive cable being inside the car. That a hazard?
 

·
Registered
Joined
·
2,999 Posts
yeah its ok to run the pos inside the car....I have two running in mine

you can ground to the frame rail, just make sure it has good continuity throughout the car
 

·
Registered
Joined
·
1,253 Posts
Yeah, my diagram gets around a lot. I ran my pos from the alternator to the battery through the firewall, under the carpet, and to the rear. The welding cable from the cutoff switch to the starter solenoid was run underneath the car.

Go ahead and ground it to the subframerail underneath the battery. But go ahead and do the ground up front (from motor to subframe). You won't have any problems...just follow the diagram.

I've been told that if you remove that wire that senses the voltage that you would get erratic outputs from the alternator, simply cause it's not exactly sure what it needs to do. As for your EEC getting fried, I dunno?? :confused:
 

·
Registered
Joined
·
713 Posts
thanks for trying to answer my question, i guess it would be possible that eratic voltage could lean towards a higher voltage
than the eec could handle boom!! im guesing here, but obviously
the eec blew after i installed a msd 6al and rewired the alternator taking my pick here, i believe it was the alternator.
 

·
Registered
Joined
·
743 Posts
Discussion Starter · #14 ·
Im planning on running the 2g battery cable the kit came with, do I still need a 1g welding cable from the alt. back? The diagram shows this cable smaller than the pos. battery cable.


This may be a stupid question, but I have to ask: Those of you who put the switch behind the license plate and spaced it, have any of you been hassled by cops for the rear light not shining on the plate? The reason I ask is that I been pulled over for that light burned out
 
G

·
You only have to bump it out about 1 1/4".
The light still shine fine down on the plate.
The 2-gauge cable is too small. Gotta go 1-gauge
or thicker or your asking for charging probs.
 

·
Registered
Joined
·
1,246 Posts
Summit sells a battery relo kit that comes with the long battery cable. Just get that. That's what I used on my 66.
 

·
Registered
Joined
·
1,253 Posts
c4mustang92 said:
Im planning on running the 2g battery cable the kit came with, do I still need a 1g welding cable from the alt. back? The diagram shows this cable smaller than the pos. battery cable.


This may be a stupid question, but I have to ask: Those of you who put the switch behind the license plate and spaced it, have any of you been hassled by cops for the rear light not shining on the plate? The reason I ask is that I been pulled over for that light burned out
First of all, the welding cable is 1/o (pronounced "one ought"). It's larger than 1g or 2g.

And Forced is right, you don't space it out all the way past the lights.
 

·
Registered
Joined
·
743 Posts
Discussion Starter · #18 ·
Is the inline fuse on the wire from the alt. crucial? If so, what did everybody use? I went to some stereo shops, and they want around $40 for an inline fuse holder. Also, what fuse do I need?
Im hoping that someone did theirs a cheaper, yet effective, way.
 

·
Registered
Joined
·
713 Posts
just in case i misread, the fusing from the alternator i fused
at 60amps. i bought the fuse at radio shack for 2 for 3-4$.
i can get you a free fuse holder for that if thats what you want.

im using a 100amp fuse on my battery, the fuse and holder was
28$ from a stereo shop, the fuse is rectangle/flat didnt have a fuse holder for that. but i can get fuse holders of most sizes
if there cylinder type.
 

·
Registered
Joined
·
86 Posts
If you have the high torque mini starter setup, you don't need to run the positive all the way to the back. You run a wire from the solenoid up front to wiring block in the back which runs to the positive on the starter (I use a block so I can hook up accessories on the block for a key on switch). (I used an 8 gauge wire for this) and then just run a ground from the battery to the frame rail. Does that make sense?:D
 
1 - 20 of 35 Posts
Top