Battery Relocation and Charging issues


New Member
Oct 21, 2001
Chicago IL
Visit site
so I bought the car and the battery was already relocated in the trunk. Extra bonous... not really. Car has a problem with recharging the battery, I go to check it out and the relocation kit is home made and pretty crappy job at that. So here are my questions...
1. The Ground is not as thick of guage as the Possitive. My guess is its a 3 or 4 guage (about 1/2 in diameter wire) and the positive is a 1 guage. and is just bolted by the trunk latch. could this cause a lack of charge in the battery?
2. should there be any sort of fuse between the positive wire and the solenoid??
3. on the solenoid is the ALT wire go on the same side that the wire from the battery goes??
thats all for now...
  • Sponsors(?)

fox racer

Jun 22, 2004
Staten Island, NYC
I) Ok, firstly, that ground is pathetic:
1)Get some 1 or 1/0ga wire and ground the battery to the quad shock mount bolt (the bolt that hold the quad shock mount on, NOT the long stud that the quad shock mounts to).
2) Get another cable (same size), and run it from the same bolt you grounded the battery, under the chassis, and mount the other end to the stock ground location on the block.
3) Finally, get another 4 ga cable, and run it from the stock ground and attach the other end to the stock EEC ground. (HINT: Just cut the battery terminal off the stock ground wire, crimp on a ring terminal, and attach it to the stock EEC ground)
II) No, not necessarily. But for the battery relocation to be NHRA legal, you need a cut off switch (Moroso sells good ones). Visible, preferably on the back of the car (Out of rear tail lights, rear license plate etc...)
III) Yes


"How long does it take to get help in here?
SN Certified Technician
Nov 29, 1999
If the alternator doesnt charge at all, the system sense-wire might have been removed by accident. It ties into the stock charge cables.

Good luck.


New Member
Oct 21, 2001
Chicago IL
Visit site
right now on the solenoid the wire coming from the battery to the solenoid that terminal is empty besides the battery cable. that wire needs the alt wire on its side or is it fine on the other side( is that where it belongs)??


New Member
Oct 21, 2001
Chicago IL
Visit site
wheres a good place to pick up that wire Napa?? do you know if they put on the end clamps... i know I had some stero **** before and it was a bitch to get that **** on. thanks guys!!


StangNet's favorite TOOL
SN Certified Technician
Mar 10, 2000
Dublin GA
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

Note: The quick disconnect may have fallen victim to damage or removal by
a previous owner. However, it is still of utmost importance that the black/green
wires have a high quality ground..

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.

For a battery cut off switch, see
is the switch 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

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 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.

The fuse & wiring in the following diagram are for a 3G alternator. The stock alternator uses a dark green fuse link wire that connects to 2 black/orange wires. Always leave them connected to the starter solenoid even if you have a 3G alternator.

See the following website for some help from Tmoss (diagram designer)
& Stang&2Birds (website host) for help on 88-95 wiring Everyone should bookmark this site.

Ignition switch wiring

Fuel, alternator, A/C and ignition wiring

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs

Vacuum diagram 89-93 Mustangs