83 mustang alternator/killswitch question

[TF83STANG]

hi guys ive searched endlessly and cant seem to really get a straight answer...so let me make this as easy as possible so maybe i can get a straight answer..

i own a 1983 mustang and recently put my battery in the trunk with a on/off switch. now i was told i need to solder a 2 gauge wire from "the mystery wire" on the alternator back to the switch....well...im trying to figure out what wire i have to cut and solder that goes back to the switch...

now i bought the car from a friend and it had been sitting in peices for 4 years...he told me he had upgraded the alternator to a slightly bigger one then the 83 came with..i believe its off a 89...but im not sure....the alternator has 2 plugs that plug into it.... one plug has a white wire with black stripe, a yellow wire with white stripe, and a green wire with red stripe... the other plug has a white wire with yellow stripe and 2 black wires with orange stripes...

my question to u is what wire do i cut and then solder to a thicker gauge wire to send back to my battery switch? im pretty mechanically savvy...i was just trying to make this as easy for everyone and me also...ill include a pic of what i am trying to say....



thank you guys...not looking for smarty pant remarks...just looking for some honest guidance!!!! thank you!!!!!

 

[jrichker]

The following is for an 87-93 car, but will work with other models that use the same wiring scheme.


For a battery cut off switch, see Moroso : Category Display
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 1/2" 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 Ford Fuel Injection » How To Solder Like a Pro 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 wire is the ignition on sense feed to the regulator. It supplies a turn on signal 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
Mustang FAQ - Wiring & Engine Info Everyone should bookmark this site.

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

Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg


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.

 

[TF83STANG]

so i cut the green wire and run it back to the switch? i have a 2 pole single throw switch...on off....it goes to the battery side of the switch correct?

 

[jrichker]

so i cut the green wire and run it back to the switch? i have a 2 pole single throw switch...on off....it goes to the battery side of the switch correct?

Do it exactly like the instructions show and it will work fine. Use the Moroso switch with the correct part number. Anything else will not work with the circuit as it is drawn.

 

[TF83STANG]

yeah im trying to avoid buying something like that...i know theres a wire u cut and just send back to my ON/OFF switch...