STICKY: 3G Interchange Facts. Read if you're thinking 3G

[Clarko]

Anyone know which 3G would work for a inline 6?

Either should work in actuality.
I'd shoot for the narrower one first but the longer one does put it farther away from the engine itself.

[jbrown414]

The PA Performance link for the adapter on the first page doesn't work. Do you have another link?

[mljjones67]

Well the alt from the sable is different looking than the 3g. So back to looking for another 3g. I will post some pics of the one out of the sable to see if it will work.

[James72]

They base the wire size on potential draw of current. Look at the little wire that comes off the Alternator terminal. They are not trying to power the truck with the alternator they are only trying to charge the battery with that little wire.

Not so, the alternator is there to run all the electrical circuits and recharging the battery after start up, the battery is there for starting only. The reason you have larger battery cables is for the starter, thats where they directy go.

65 Amp alternator needs 6ga
100 Amp - 3ga
125 or 130 Amp - 1 ga.

Also, these numbers are for continuous max current, if you have a 100 amp alt putting out 100 amps continuously you have a bigger problem then wire size. Your alt will put out 20-30 amps during normal use nomatter what it's rated for, it may max out for a few seconds after start up but thats all. Your starter can pull 300amps or more through 1 or 2 ga. and even smaller, these cables are rated for momentary use which is usually double to triple the current compared to the continuous rating. So you don't need to wire up welding cables to your alt.

[occupant]

Sweet. Then when my wife's '99 Taurus finally bites it, I can snag the alternator before it goes to the crusher, and keep it for whatever truck I get next.

[crazyhorse]

3G's rule, I put one in my 89 mustang and on my 68 f100 when it had the original 390 and now it's on my f100 with the fuel injected motor, I also put one on my friends 67 lincoln that has a 460. I used 90's taurus alternators for all of them cuase of the way the mounting points are.

MARZ = can you give me any info on the mustang upgrade? i need to make that change on mine. thanks for any advice.

[71HANKER]

Ive been trying to figure out how to upgrade my charging system to handle my offroad lights and my winch. The 3G alternator swap looks fairly simple, and i know i can do it, but how can you tell which late model cars have the 3G alternators, and how much they put out? im looking for a 130amp or more. Maybe some can shine some light.

[Thunderfoot]

Ive been trying to figure out how to upgrade my charging system to handle my offroad lights and my winch. The 3G alternator swap looks fairly simple, and i know i can do it, but how can you tell which late model cars have the 3G alternators, and how much they put out? im looking for a 130amp or more. Maybe some can shine some light.

There are 2 sizes of cases for the 3G alternators... The smaller is 95A and the larger is 130A, also the cooling holes are different in the front of the case. see picture below...
Looking at the parts cross reference for the 130A alternator that has the right case configuration it was in:
94-2000 Mustangs
94-97 Thunderbirds
94-97 Cougars
There may be others, this was just a quick look at Part America for a 94 Mustang alt and what else it fit...

[reflectionpoint]

Hey all,

Think I cut too deep.. haha. Guess cut isn't the right word.. just unplugged too much.

I started the swap by unplugging the alt/regulator harness from the regulator, alternator, and the chassis harness near the starter solenoid. Taking it home and fabricating my new harness. I looked at three different online diagrams and a Product Service Bulletin from AutoZone (Document TT-546, attached). I made my new harness with all new components and disregarded my old harness.

Install went great, needed a new bolt for the top of the alt because it wasn't threaded like the original, but not big deal. Got the wiring attached and was ready to go. I noticed the two connectors to the chassis harness and wondered why the diagrams didn't seem to take them into account other than the LT Green/Red for the Ammeter. I'm thinking I cut too much out? My question is which of these are really necessary for the truck to start and operate correctly.


Complete harness as removed from truck (after removing shrink tape) sorry for the poor quality.


Plugs closest to the solenoid, the ones that the other harness DIDN'T take into consideration.

I have figured a couple of the wires, but I have learned sometimes playing dumb and not assuming gets you in less trouble in the end.. so I left the assumptions out.

Politely, how to I need to cut and wire this bit of harness into the system? I know that the cab is getting no power now due to this not being connected and the truck will not start because of this. I plan to cut the 'plugs' off of the truck-side of this harness and make new connectors so everything is clean and OEM-ish.

The wiring I did followed this diagram: http://www.fordification.com/galleries/ ... nstall.jpg I connected the Lt. Grn/Red off the alt to the Lt. Grn/Red from the truck.

[reflectionpoint]

This is that Product Service Bulletin, showing both a 1-wire setup and a more traditional setup. Available from AutoZone listed for the 3G alternator in a 1996 Ford Mustang V6, which is what I installed in my F100

[Thunderfoot]

Hey all,

Think I cut too deep.. haha. Guess cut isn't the right word.. just unplugged too much.

I started the swap by unplugging the alt/regulator harness from the regulator, alternator, and the chassis harness near the starter solenoid. Taking it home and fabricating my new harness. I looked at three different online diagrams and a Product Service Bulletin from AutoZone (Document TT-546, attached). I made my new harness with all new components and disregarded my old harness.

Install went great, needed a new bolt for the top of the alt because it wasn't threaded like the original, but not big deal. Got the wiring attached and was ready to go. I noticed the two connectors to the chassis harness and wondered why the diagrams didn't seem to take them into account other than the LT Green/Red for the Ammeter. I'm thinking I cut too much out? My question is which of these are really necessary for the truck to start and operate correctly.


Complete harness as removed from truck (after removing shrink tape) sorry for the poor quality.


Plugs closest to the solenoid, the ones that the other harness DIDN'T take into consideration.

I have figured a couple of the wires, but I have learned sometimes playing dumb and not assuming gets you in less trouble in the end.. so I left the assumptions out.

Politely, how to I need to cut and wire this bit of harness into the system? I know that the cab is getting no power now due to this not being connected and the truck will not start because of this. I plan to cut the 'plugs' off of the truck-side of this harness and make new connectors so everything is clean and OEM-ish.

The wiring I did followed this diagram: http://www.fordification.com/galleries/ ... nstall.jpg I connected the Lt. Grn/Red off the alt to the Lt. Grn/Red from the truck.

The Node looking thing is a Fusible link in the wire.
The Black / Yellow wire is the “Main power” to the cab of the truck. Power to the ignition and to everything else from there…
The Yellow wire is for the Amp meter, there should be a Red wire as well that is for the amp meter.
The Light Green / Red striped wire is the “Exciter” wire for alternator. You will need this for the new alternator.

You can look at these two different diagrams to help fill in the blanks…
This one is for the light instead of the amp gauge but has the connectors like you have. http://www.fordification.com/images/sch ... rging2.jpg
This one is for an Amp gauge but the connectors are a bit different. http://www.fordification.com/images/sch ... gauges.jpg The wire codes are the same through each…

Hope this helps.

[reflectionpoint]

Hope this helps.

Got it. Did it. Running. Thank you.

I connected the Black/Yellow to the battery directly as the starter solenoid post was running out of room. Connected lt. green/red to lt. green/red. Hooked up this way everything works, lights are bright even with the fans blowing in the cab and it tested 14.42v no loads, 14.35v with load at the battery so the regulator and wiring are working. When I say everything, the ammeter is not working and I could care less, it's getting a shiny new voltmeter soon.

As far as controversy about wire gauges, I like 'welding cables'.. Main lead from the alternator is 2ga, battery and starter leads are also 2ga. Lt. Green/Red and Yellow/White wires are 10ga. Lead connected to Black/Yellow is 10ga with 30a inline blade type fuse to replace the old in-line fusible link. I used a 150 amp Circuit Breaker on the main lead from the alternator. I liked this better than the 'mega-fuse' idea.. hate blowing a fuse and not being able to find a new one handy, or blowing the spare because you weren't smart enough to fix the short/overload first (guilty!).

To make my 'harness' I bought the connector pigtail from Napa because I was not using old parts or a junkyard pull so I had to start from scratch.. I felt this would give me the best idea of how to do this type of harness so I could replicate it easier in the future and possibly make a harness for a friend in another state, etc.

Will post pics of install after it comes back from the exhaust shop!

[Menace Kustoms]

I'm doing a new universal harness in my truck. It's set up for a one wire alternator. Which one can I use that's 3G and one wire?

[Thunderfoot]

For those looking for the answer to this last question follow this link. http://www.fordification.com/forum/view ... 69#p516738

[Menace Kustoms]

Ive been trying to figure out how to upgrade my charging system to handle my offroad lights and my winch. The 3G alternator swap looks fairly simple, and i know i can do it, but how can you tell which late model cars have the 3G alternators, and how much they put out? im looking for a 130amp or more. Maybe some can shine some light.

There are 2 sizes of cases for the 3G alternators... The smaller is 95A and the larger is 130A, also the cooling holes are different in the front of the case. see picture below...
Looking at the parts cross reference for the 130A alternator that has the right case configuration it was in:
94-2000 Mustangs
94-97 Thunderbirds
94-97 Cougars
There may be others, this was just a quick look at Part America for a 94 Mustang alt and what else it fit...

Make sure and order one for a V6. The V8 is a bottom mount.