Battery Relocation Q

Aaron'S'tang said:

For those of you who have done it. What is the best route to run the positve cable? Also, will I have to drop the tank or anything to get to the underside of the trunk to secure things? Thanks for the help.

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I know a lot of people say it is a bad idea, but I ran my cable threw the inside of my car on the drives side. I removed the cruise control stuff which will leave a nice hole you can use to exit the fire wall. I mounted my battery on the drivers side, so I did not have to drop the tank, if you do it on the passengers side you will. Good luck.

My car had the relocation kit installed when I got it but the positive cable is run inside the car along the drivers side tied in with the other factory wiring harness. Then just take the route of choice once you get into the trunk area. My battery box is attached with the supplied big self tapping screws so you dont have to get at it from the bottom. Just make sure your clear underneath when you drill.

The 2 gauge wire kits aren't enough. You need 1 or 0 gauge cable (welding cable works good and is cheap/plentiful). Dropping the tank isn't too huge a pain, if you're doing a fuel pump, but just to run some battery cable ...?? I don't see how it'd be necessary. Just be extra cautious about where you drill so you don't poke an extra hole in the tank...

Rear mounted battery ground wiring. Follow this plan and
you will have zero ground problems.

One 1 gauge or 1/0 gauge wire from battery negative post
to a clean shiny spot on the chassis near the battery. Use
a 5/16” bolt and bolt it down to make the rear ground.
Use a 1 gauge or 1/0 gauge wire from the rear ground
bolt to a clean shiny spot on the block.

One 4 gauge wire from the block where you connected
the battery ground wire to the chassis ground where the
battery was mounted up front. Use a 5/16” bolt and bolt
down the 4 gauge engine to chassis ground, make sure
that it the metal around the bolt is clean & shiny. This
is the alternator power ground.

The computer has a dedicated power ground wire with
a cylindrical quick connect (about 2 ½”long by 1” diameter.
It comes out of the wiring harness near the ignition coil &
starter solenoid (or relay). Be sure to bolt it to the chassis
ground in the same place as you bolted the alternator power
ground. This is an absolute don’t overlook it item for EFI cars

Picture courtesy of timewarped1972




Crimp or even better, solder the lugs on the all the wire.
The local auto stereo shop will have them if the auto parts
store doesn't. Use some heat shrink tubing to cover the lugs
and make things look nice.

For a battery cut off switch, see http://www.moroso.com/catalog/categorydisplay.asp?catcode=42225
is the switch http://www.moroso.com/catalog/images/74102_inst.pdf is the installation instructions.
Use the super duty switch and the following tech note to wire it and you will
be good to go.

Use the Moroso plan for the alternator wiring and you risk a fire. The 10
gauge wire they recommend is even less adequate that the stock Mustang
wiring.

There is a solution, but it will require about 40' of 18 gauge green wire.

Wire the battery to the two 1/4" posts as shown in the diagram.

The alternator requires a different approach. On the small alternator plug
there is a green wire. It is the sense lead that turns the regulator on when
the ignition switch is in the run position. Cut the green wire and solder the 40'
of green wire between the two pieces. Use some heat shrink to cover the
splices. See http://fordfuelinjection.com/?p=7 for some excellent
help on soldering & using heat shrink tubing.

Run the green wire back to the Moroso switch and cut off the excess wire.
Try to run the green wire inside the car and protect it from getting cut or
chaffed. Crimp a 18 gauge ring terminal (red is 18 gauge color code for the crimp
on terminals) on each wire. Bolt one ring terminal to each of the 3/16" studs.
Do not add the jumper between the 1/4" stud and the 3/16" stud as shown it the
Moroso diagram.

How it works:
The green wire is the ignition on sense feed to the regulator. It supplies power
to the regulator when the ignition switch is in the run position. Turn the
Moroso switch to off, and the sense voltage goes away, the voltage
regulator shuts off and the alternator quits making power.

See the following website for some help from Tmoss (diagram designer) &
Stang&2Birds (website host) for help on 88-90 wiring and lots more…

http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

Diagram courtesy of Tmoss and Stang&2birds.

Reliablity is the key. Use the #1 or #1/0 cable and you'll never have to wory about the voltage drop along the cable.

Aaron'S'tang said:

And then as far as the extra ground go, chasis to block, the other I forget. It says this is a must in your post. Just curious why the kit instructions don't tell you this? I appreciate your help, thanks.

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The "absolute don’t overlook it item for EFI cars" is a strictly for Mustangs item. It is the computer power ground. Skip or skimp on it and your twin turbo AFR headed 347 stroker will be overrun by some dinky import with a fart can muffler. It is a must for the computer to have a proper power ground to operate at peak efficency. The battery box kits are universal and made so that one size fits all. The companies that build them are leaving the small but important details up to you.

The 4 gauge block to chassis ground wire is the alternator power ground. A prefab cable in the form of a starter solenoid to starter cable works good here. They come in various lengths and have the lugs crimped on the ends.