6g alternator q's

[mob]

Hey guys, i got a alternator from the parts store for a 94/95 mustang gt, the part number was p7771-11-6g so im guessing its a 6g correct? I have a couple quick questions because when I search it doesn't register the 6g, and most questions are for 3g's. I got from searching that you don't need to splice the stator wire. So what do you do? Do you just discard that whole harness? Use the stock stator wire? Just leave it unplugged?

And also for the ground wire, I kept reading to run a 4 gauge ground wire from the block to the chassis? I don't get this, can someone explain what exactly this does? does the alternator harness have a ground somewhere to the chassis, and finishing that ground to the block will ground it better? I'm a little confused how that works, and where exactly is a ground wire connected to the alternator? Does the ground from the block have to be put anywhere specific?

I got this quote from Jrichker:
"Any car that has a 3G alternator needs a 4 gauge ground wire running from the block to the chassis ground where the battery pigtail ground connects"

Where exactly is the chassis where the battery pigtail ground connects? My battery is in the trunk so I am a little confused by this, again does it have to be anywhere specific, or just 4ga from block to chassis that's it.

And last question does anyone know stores that sell those fuses? I guess the fuse I want to use is a 150amp water fuse? That's what its called right? Anyone know if places like napa, ace sell those?

 

[mob]

Wait this is the alternator I have, does the fact that I have a stator plug on it mean its a 3g? If this is a 3g the only thing I need to know about is the ground wire. Thanks.

 

[HISSIN50]

Looks like a stator circuit and thus a 3G. That would be my preference anyhow. Just loop the stator wire from the regulator harness to the solo port on your 3G case.

JR has put up a picture of the sheetmetal ground where the EEC ground connects. As long as you add another ground from the engine to the frame or body, you're good IMHO (this isnt as ideal as JR's method, with regard to common grounding points, but functionally it works well).

The alt grounds through its mounting bracket and through the engine. This is why you want the extra ground path (from motor to chassis ground).

Fuse the alt for the weakest link. I would probably try a 125 amp fuse, since your length of 4 AWG might not be rated for 150 amps. Your local Napa should sell the fuse and holder. Pep or AZ in your area might as well.

Good luck.

 

[mob]

Thanks alot hissin, everything I needed to know, Im gonna try this saturday or sunday.

Oh and I dont need to swap out the voltage regulator right? Use the new one?

 

[BK_CAULEY]

unless you have an aftermarket regulator use the one that came on it from the parts store. most of the time the only part that fails on these are the regulators.

 

[Foxfan88]

i did the 3g alt swap using the exact same alt (part store 94-95 130A unit)

there will be a little grinding required to get the new alternator to fit, the case is larger and the stock fox alt bracket needs a little massaging with a die grinder and cutter, doesnt need to much, just take the bracket off and you will be able to see where it needs ground down some to fit, also, the upper ear on the new alt isnt threaded like a fox alt.
you will need to get new bolt and a nut to properly fasten the upper ear.

as for the wiring, i forget the wire colors exactly.

but there are two connections that plug in a fox alt, one of them has two larger blk/org and one small wht/blue, i am not 100% sure on the colors as i havent looked at them lately but you will know what i am talking about, its the wide connector with the 2 larger wires and one small wire.

what you will do it cut the small wire from this plug, take the stock plug with the two remaining larger wires and tape it up or something, just get it out of the way safely.

now the small wire you cut, it needs to be connected the small male terminal in the 3g alt. you can used a small crimp on female spade connector, thats what i used.

now the other of the two factory plugs, it will just plug right in the new 3g with no modification.

now you need to run a wire from the stud on the 3g to the hot side of the starter solenoid, i used a 4ga wire and some brass eyelets. you will need to fuse this wire.
i used a 150A wafer fuse, i searched amazon.com and found a fuse and case for like 15$


as for the extra grounds, extra grounds in a good idea on any car. cant ever have too many grounds.

i have a 2ga grd running from the motor mount bolt to a hole on the swaybar mount ( not runnig a sway bar)

you can place the ground wherever you want, just connect the engine to the body somewhere.

not sure if you knew all this but i figured i'd post, i did the exact same thing your fixing to do some so i figured it help some.

the 3g 130A alt charges alot better than a crappy fox alts.
i did the swap when i did my efan swap. the alt works killer.

good luck.

 

[Nova]

sorry, i was too lazy to find the exact page, but there is a good bit of info in this forsale thread:

3G Alternator Upgrade Complete Kit Small case - Corral Forums

 

[mob]

Thanks foxfan for the info I read jrichkers write up so I pretty much am all set, good to know I will need a new bolt and nut though, thanks. You think I can trim the bracket with just a diegrinder and some stones? Or will I need a cutter?

And also do you know what size bolt I will need for the top ear? 1/2 maybe? I dont wanna have to run back and fourth a bunch of times or buy a bunch, maybe ill just go up there and use one of the alternators in stock and test fit it there

 

[Foxfan88]

Thanks foxfan for the info I read jrichkers write up so I pretty much am all set, good to know I will need a new bolt and nut though, thanks. You think I can trim the bracket with just a diegrinder and some stones? Or will I need a cutter?

And also do you know what size bolt I will need for the top ear? 1/2 maybe? I dont wanna have to run back and fourth a bunch of times or buy a bunch, maybe ill just go up there and use one of the alternators in stock and test fit it there

stones would work but take a little longer, a good carbide cutter will eat away at the aluminum real fast. but its no reason to just go out and buy one if you have some stones laying around.

IIRC the bolt i used was either 3/8 or 7/16

just get one that fits in the upper ear good. the hole on the top of the fox alt bracket is pretty big, so what ever fits through the ear on the alt will fit through the bracket.

 

[mob]

k sweet, did you have to get a new belt? Or are the pulleys the same size?

 

[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
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..

The screwdriver points to the common body ground point for the battery and extra 4 gauge alternator 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.

 

[mob]

Thanks for the diagram Joe.

 

[HISSIN50]

k sweet, did you have to get a new belt? Or are the pulleys the same size?

I used the same (OEM) belt.

I've also overdriven (1 7/8") a 3G and used the same belt.

The tensioner gives you some fudge factor.

FWIW, I used a 6" hacksaw on the bracket. It worked fine. A sharp butterknife would almost work.

 

[Foxfan88]

my same belt worked also.

 

[mob]

I ordered a fuse and holder like this from napa, 125 amp, that should be good right?

 

[HISSIN50]

That's a nice little fuse and fuseholder.

 

[mob]

yea only like 20 bucks total which isnt bad, I couldnt find a 125amp on parts-express.com, and audio excellence wanted like 50 bucks for a holder and fuse.

part numbers are 782 1143 and 782 1137 at napa, if anyone in the future wants to get the fuses there.