3G page is up - need more info, pics, tips, and suggestions

[86VickyLX]

Now there's one more thing I"m a little confused on, you can either use the white/black wire on the fire prone plug as the stator, or you could just jump it from the middle wire in the regulator plug for your stator. Is it the same wire? Just wanted to clear that up.

[gadget73]

If you un-tape the stock harness a bit, you'll see that the white/black jumps between the two plugs. On a 3g, it goes to the small connector on the side. You can use either your original 2g regulator plug and an appropriate crimp connector to do the job, or rob the one off the Taurus and splice the green wires together. Functionally, its the same. The correct Taurus plug will clip in there a bit more securely.

[1987cp]

The green wire is neccesary. It goes to the ignition circuit and switches on the alternator. No green wire = no charge. Externally regulated models have the same green wire to the I terminal on the external regulator. Functionally there is no real difference between an internal regulator and external regulator. They have the same connections, just physically in a different place.

This reminds me, is there any real functional reason not to use a high-output 1G instead of a 3G?

[86VickyLX]

If you un-tape the stock harness a bit, you'll see that the white/black jumps between the two plugs. On a 3g, it goes to the small connector on the side. You can use either your original 2g regulator plug and an appropriate crimp connector to do the job, or rob the one off the Taurus and splice the green wires together. Functionally, its the same. The correct Taurus plug will clip in there a bit more securely.

Thanks Thain. I think all my 3G questions have been answered.

[gadget73]

This reminds me, is there any real functional reason not to use a high-output 1G instead of a 3G?

Not really, just the low rpm output of a stock 1g isn't that great, and often when modified its even worse. I'm not sure the specifics but usually when alternators are modified for more power output, its done at the expense of low rpm performance. I'm also personally not a fan of the idea of a specialized custom-order alternator that would need to be sent away for replacement or repair. If my 3g blows up tomorrow, I can drive to Napa or Advance and probably get one off the shelf. Availability of replacement parts is important for me.

[86VickyLX]

Not really, just the low rpm output of a stock 1g isn't that great, and often when modified its even worse. I'm not sure the specifics but usually when alternators are modified for more power output, its done at the expense of low rpm performance. I'm also personally not a fan of the idea of a specialized custom-order alternator that would need to be sent away for replacement or repair. If my 3g blows up tomorrow, I can drive to Napa or Advance and probably get one off the shelf. Availability of replacement parts is important for me.

Especially since we don't have many replacement parts for our cars available to us now.

[85crownHPP]

I haven't had any problems finding parts for my cars....

[91waggin]

Not entirely certain, 91Waggin claims he got his 3G from a 3.8 Taurus Wagon and it was a small case 3G.

I found out I was wrong. it was from a 3.0. forgive my idiocy.

[fordktpjoe]

OK, so let me see if I got this straight..all this talk of large case vs. small case and needing rare bracket vs, grinding bracket vs. alt fitting perfectly, and adding the white wire to the harness and something about a green wire has me just a tiny bit cornfused.:confused:

Seems like someone said a page or so back that if I grab the whole harness out of the 3.0 Taurus, (or was it the 5.0 Mustang?) that it'll plug right into the factory harness on my '90 Vic, and then all I gotta do is add the charge wire to the Batt. or solenoid with a fuse, of course...I would just buy this charge cable setup off of that site that sells all that stuff.

Is this correct, or did I misunderstand something?

[91waggin]

@fordktpjoe.....

I'm going to assume your CV does not have the heated windshield, because very few of them did. (If you do, you'll have a button that says "w/s de-icer" on your dash.) The cars without the heated windshield came with a 65-amp, internally regulated (by 1990, anyway), small-case alternator. The small-case alternator from a 3.0 Taurus bolts right up; although you may have to change the pulley. I didn't have to, but others have said they did.

The business with grinding the bracket and large case alternators and stuff doesn't apply if you've got a small case 2G alternator to begin with.

Anyway, after you get the alternator bolted up to the engine and the belt on, the rest is quite simple. On your old 2G alternator there were 2 plugs--one had the charge wires and one was the regulator plug. The regulator plug plugs right into the matching port on the new 3g alternator.

Then, get yourself a big fat charge wire (I used a 4ga battery cable and put new ends on it), and a 175a fuse. This fuse looks like this

and can be found at some parts stores, or somewhere on the charging circuit of the 3.0 Taurus--the OEM fuse off the Taurus has a cool little Ford oval on it, if you care, otherwise it's just easier to get it from a store. BTW the alternator in the above pic has its regulator plug showing--the big white plug.

Also, in the above photo, you can see a single-wire plug next to the regulator plug (mine has a little blue terminal end in it). When you harvest the 3g alternator, get the plastic terminal clip that was on here and give yourself a couple inches of wire, then cut it off and take it with you.

Examine the 2g alternator charging wires. On the same plug as those two 12ga wires there should be a smaller wire, but I can't remember off-hand what colors it has. In any case, it's a noticeably smaller gauge than the two charging wires. Cut it off from the plastic plug that was for the 2g alternator, and splice that wire to the wire/terminal you got in the previous paragraph. Plug it into the single wire terminal next to the regulator plug on your new alternator.

To make what I just said simpler, I have pictures:





All of the above should be disregarded if your car came with a windshield de-icer or was not equipped with a small-case alternator to begin with. I posted what worked for me.

[fordktpjoe]

91 waggin. Naw, I don't have the heated windshield. You just gave me an explanation that made the whole process as understandable and easy as everyone says it is. looks like I can use my 2G harness on the 3G alternator.

Thanx mang!

Couple more questions though.

In the top photo, where it shows the wire to cut (looks maybe white, or tan)
that would leave two wires on that second plug (one on the right in the pic)
what do I do with that plug after I cut the white wire off? just let it hang? Or whack the other two wires off and toss it? maybe trace the other two wires back to the end and cut 'em there, and pull 'em outta the loom? Or use my imagination? I am assuming it doesn't get used anymore.

And... rjminjection has the harness and charge cable "pre-made" could a fella go this route?

[91waggin]

The other two are the old charge wires. They run around in a harness behind the headlights to the starter solenoid by the battery. I traced them from the alternator down to where they go into some sort of plastic plug, cut them there and taped them off. Remember, they still have +12v, so make sure you've done a good job preventing them from grounding. Others that have unhooked the old charge wires from the solenoid side have had some strange problems; there must be something somewhere in the harness that uses them.

If you use pre-made stuff, it'll probably end up looking a lot better than reusing factory wiring, BUT it'll be a lot more wiring and a lot more work and (more than likely) a lot more $$$--although it looks like they have a nifty fuse holder for the 175a fuse. But if you go to this page:

http://www.grandmarq.net/vb/showthread.php?t=23501&highlight=3g

You can see how I did it. Lot more hokey, but quicker and cheaper and the car ran again that day instead of waiting for shit to get shipped.

And that wire is white with a black stripe. It's just dirty in the photo. The other end of that wire is actually just over on the regulator plug, in the middle, so if you want to clean up the factory harness some, you can.

In the same vein, Ford, in their infinite wisdom, ran the yellow wire from the regulator plug (this is a +12v sense wire) all the way over to the starter solenoid, probably to take into account the long, high resistance path for the charge wires. The premade kit you mentioned simply runs that yellow wire over to the charging stud on the alternator (there shouldn't be much voltage drop on a 4ga cable). This makes the only wires that actually leave the alternator are the green/red wire on the regulator plug (charging system idiot light) and the charge cable itself. That's all the rjm harness is.

Cheers!
--Graham

[86GmLsCoupe]

And... rjminjection has the harness and charge cable "pre-made" could a fella go this route?

I went that route, it's certainly not necessary but it was brandy new, came with easy instructions I was lazy. RJM makes nice stuff.

[fordktpjoe]

86GmLsCoupe.... Nice clear pics..Thanx. Could you take a shot of the connection where the rjm harness plugs into the factory harness?

Also, when you order the charge cable, you have to specify a length, and a fuse size...what did you wind up getting?

[86GmLsCoupe]

86GmLsCoupe.... Nice clear pics..Thanx. Could you take a shot of the connection where the rjm harness plugs into the factory harness?

Also, when you order the charge cable, you have to specify a length, and a fuse size...what did you wind up getting?

No problem, glad the pics helped you out some. With the RJM harness, you ditch ALL of the old wiring, every single bit. The only wire you need from the original stuff is the green wire which is added to the harness with a nice weatherpak connection. In the pic below, you can seen where I tucked the old regulator plug by the alarm siren so that if for some reason I loose my mind and wanted to back to the 2G, I could. The other methods involves acquiring a 3G harness from the donor vehicle or modifying your existing regulator plug. As you can see, my plug looks pretty poopy and I'm not experienced with wiring so I got the new one. IIRC, I believe I ordered around 5 or 6' of red for charge and some of the black cable to redo the grounds though I'd measure to be safe. I used 175 amp inline fuse and have a few spares I keep handy. I know Scott mentioned using a breaker instead so there's no need to search for a fuse if it ever did pop. From what I recall you don't want to go to undersized with the fuse because if it does pop, that can cause damage to the alternator and other electrical components as well, though like I said, I have basic wiring & electrical knowledge.