Please tell me i have this right!

[KLEAN COUPE]

I am about to undertake a battery relocation to the trunk of my 91 coupe.

I would like to confirm i have the process down right.

Cables 1/0 guage welding cable or the equivilent.

Run the positive cable from the positive post on the battery through the car(inside or outside)to the positive post of the starter solenoid(left front fender)

Run the ground from the negative battery post to the rear quad shock bracket, then run another ground from the quad shock bracket up front to the factory ground on the front of the block, near the oil filter, then from there up to the factory eec mounting hole on the left front inner fender.

Assuming this is correct, you guys who have done it this way, did you route the ground back into the vehicle from the quad shock bracket throught the trunk again then up front to the factory grounding point on the front of the block?

PS. This car does not go to the track so i wont be installing a cut off switch. Thanks in advance for all your help

 

[speedytang]

To save yourself a bunch of headaches, run the ground front to back like the positive cable. You will be glad you did.

 

[jrichker]

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 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.

 

[Bossnutt]

I'm glad you asked this, going by what I've read my friend is doing it all wrong.

 

[TrickFlowd]

this is helpful info to me also...

 

[stykthyn]

this should be a tech sticky. great thread!

 

[KLEAN COUPE]

so my routing is correct then for the ground as per the diagram jrichker has provided, Thanks for all the replies. I guess im now wondering do more of you run the cables underside or in the car?

Thanks again

 

[jrichker]

Run the cables inside the car if at all possible. They are subject to damage if you run them outside.
Run over a hubcap someone knocked off and it slices your positive cable or even the ground and
you have a big problem.

For those of you who need a battery cutoff switch, here's the how to do it...

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
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 1/2" posts as shown in the diagram.

The alternator requires a different approach. On the small alternator plug
there is a green wire. On the diagram it is #904, lt green/red wire that connects
to the alternator and dash light. 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 1/2" stud and the 3/16" stud as shown it the
Moroso diagram.

How it works:
The green/red 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.

This setup uses a 125-150 amp fused power lead for a 3G Alternator.
For the stock alternator, you can omit the fuse & 4 gauge wire and use the stock power wire.

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.