3g alternator conversion question

[Steve83]

...it appears that this yellow from the old voltage regulator should be connected to the "A" post on the 3g alternator/regulator.

No, it should be cut off & capped.

Black wire with the fusible link (38A) stays connected to the starter relay.

Yes.

...Green/red wire...should be connected to the "I" post on the 3g alternator/regulator.

Not directly - it should be spliced onto the LG/R wire on the 3G harness.

On the 3g alternator/regulator plug, it has the white/black wire (4) that just loops over to the actual alternator.

If you have a 6V carburetor choke heater, it can be spliced into that wire. Otherwise, it just stays like it is.

...an orange wire (35) that gets removed.

Yes, that circuit is internal to the 3G.

The black/yellow wire (37) that goes to the 1g alternator "B+" post gets capped off. No longer used.

It CAN be used, but not for any load that could pull more than ~30A, and certainly not for the 3G output.

The Black/red (26) between the old voltage regulator and the alternator gets capped off.

It could get discarded like Or 35; that circuit is obviated by the 3G VR being screwed to the 3G case.

A new 4awg cable is connected to the "B+" post on the 3g alternator and goes to an inline 175 amp fuse, then on to the Positive side of the starter relay (C211).

But if you're using the 3G harness, that's already included & built - you only connect the ring terminal from the short side of the fuse to the starter relay B+ post.

New 4awg cable from the Positive side of the starter relay to the Positive battery post (C211 to C207).

If your existing red B+ cable is in good condition, it can stay where it is - a new one isn't necessitated by the 3G.

...Negative side of the starter relay...

No such thing, so no such wire. One large post on the starter relay is always B+; the other post is momentarily connected to that (so also B+) during cranking.

New 4awg cable from Negative battery post to a ground post on the engine block...

Again, only if there's a problem with the existing black B- cable. And for the best electrical grounding, that cable should also be grounded to the frame (by soldering a tab to it, and then screwing the tab to the frame), and a smaller (~8~12ga) ground wire should go from the B- clamp to the inner fender or core support to a spot without paint so it makes a good ground to the body sheet metal (like the old Bk/R 26).

Brown wire (262) stays connected to the "I" post on the starter relay (C214).

The ignition system is not impacted by the 3G, so yes that wire stays where it is.

Red/blue (32) wire stays connected to the "S" post on the starter relay (C213).

Right - cranking is also not affected by the 3G.

 

[DirtDonk]

No, it should be cut off & capped.

Here's where I think we've been at odds Steve. .
I'm saying to utilize the existing Yellow wire to connect to the Yellow w/white from the donor Expedition, while you're saying just run the Expedition wire to a battery reference point?
Since I think you were one of the proponents of wiring an internally regulated alternator the same way the factory did it. With the sensing wire run over to a 12v source closer to the battery. Rather than looping it right over to the BAT stud of the alternator, then perhaps you're just saying use the new wire completely and leave out any old wires?
Do we know just how much wire is remaining on the original 3g connector?
Got a pic of your donor wiring connector dmoses?
If you've got plenty of the new Yellow w/white wire, then Steve's method would be perfectly fine. Either his way (only new wire) or my way (splice into the old wire) is a viable option if you have enough wire on the donor plug.
Either way you only need one new connection. I think we both like to keep self-connections to a minimum, in order to keep future failure points to an absolute minimum.

So just how much Yellow w/white wire do you have on your new connector?
Or, for that matter, how much of the Green w/red as well?
Got a pic?

Thanks. Sorry for stirring the pot so much over one detail. But I think Steve and I both prefer you connect the sensing wire to a point nearer the battery. Just like the factory does it.

Paul

 

[Steve83]

...you're saying just run the Expedition wire to a battery reference point?

No, I'm saying the 3G harness that I recommended & that he showed in an early post in this thread is already built to handle all of that, and that it should be used without modification (other than maybe adding a choke heat splice if applicable). That harness contains the entire Y/Wh wire, and it's already routed properly. The old Y wire from the Bk splice to the 1G VR is unnecessary.

 

[DirtDonk]

OK gotcha. I did go back over the thread looking for that picture that I thought I saw as well. Didn’t see it, but I must’ve glossed over it.

 

[DirtDonk]

OK, I saw the part about the fuse holders falling apart and thought he was sourcing all different stuff. I see that the rest of the harness is being utilized.
So dmoses, do what Steve said and get rid of your original yellow wire and utilize the wires that you now have completely.
Just like the factory did it on the donor vehicle, only with your new fuse holders.

 

[dmoses42]

No, I'm saying the 3G harness that I recommended & that he showed in an early post in this thread is already built to handle all of that, and that it should be used without modification (other than maybe adding a choke heat splice if applicable). That harness contains the entire Y/Wh wire, and it's already routed properly. The old Y wire from the Bk splice to the 1G VR is unnecessary.

This is all I was trying to ascertain in my first post. What to do with the old yellow wire if I'm using the Expedition setup. Thanks guys, I appreciate it.

Don

 

[DirtDonk]

Yeah, sorry Don. I forgot you had a full charge harness from the donor Expedition. So I was just trying to explain how you'd do it without one.

Paul

 

[dmoses42]

And for the best electrical grounding, that cable should also be grounded to the frame (by soldering a tab to it, and then screwing the tab to the frame)

Steve, regarding the B- cable, do you have a picture of something like this? I'm having a hard time visualizing this. Thanks.

 

[ba123]

I'm skimming this thread and gotta say, I can't even read it.

Why do all this stuff instead of a one wire alternator? Is this that much less expensive or something?

Sounds like such a headache.

1) You clean the mounting surfaces and protect for good ground.
2) You run fused power from the battery to the Alternator
3) Wait, there is no step 3...assuming it's a self-exciting alternator like mine is.

 

[DirtDonk]

All right Ben, no comments from the peanut gallery please!
Actually, some reasons being, it’s not Ford, if it’s a 1-wire, it’s not always readily available off the shelf, and whatever other reason.
And probably since this is sourced from a donor Ford vehicle, it gets connected the way Ford did it.

 

[ba123]

ouch!

There are Ford ones, both stock like the WH one that is one-wire but not self-exciting I think and a few Explorer versions(I have the Powermaster Explorer one).

They are still technically Ford, certainly not from any other car, just been modified to be better than stock.

 

[dmoses42]

I've collected many used but more modern parts over the years and never really had a place or the time to put them to use. As I have stated in several threads before, I bought this Bronco in 1993 in North Dakota and drove it for several years before a smoked turn signal switch and a cross-threaded steering wheel nut put it on the back burner before the turn of the century. Fast forward to now, I've retired from the military and bought a house with a 5 stall garage and a barn, so now I have time and room to start working on it again. Eventually, it will get a full restoration with Explorer EFI (I reworked the harness for that during the COVID break) and 4R70W, but right now I just want to get it moving, turning, and stopping under its own power again. I don't like to get rid of things that are still useful, I grew up really poor. Since I have this stuff (though I'm still trying to find some of it after moving) I'm going to use it. Even when I restore this Bronco with the Explorer engine and transmission, the parts I remove during restoration won't be going to waste, because I have a '77 frame I bought years ago that everything I remove will go onto. I've sourced everything to have a fully functioning running gear and the old body from my '72 will likely go onto it. I've always wanted to learn to weld, so this '72 body will be the perfect candidate to learn on. So that's just a little snippet of why I'm doing things the way I am. Unfortunately, the way I ask or communicate things tends to confuse people. But I'm left-handed so.... Maybe that has something to do with it.

 

[Steve83]

Steve, regarding the B- cable, do you have a picture of something like this?

It's the big black one connected to the (-) post of the B(attery). These show later trucks, which are better-grounded because the cable has a tab soldered in the middle screwed to the frame, and (on '92-96) a small body ground wire to the inner fender.

It's very easy to add the frame tab using a scrap of Copper tubing, some solder, and a propane torch.

 

[Steve83]

Why do all this stuff instead of a one wire alternator?

Count all the wires going to your 1-wire alternator. Then count what's shown in the pic of the 3G harness - not at the alternator end, but at the truck end. There's 1 big wire going to the starter relay's B+ post, and 1 small wire going to the instrument cluster. So a standard 3G is a 2-wire alternator. Are you in such a rush that you can't connect 2 wires? You only have time for 1?

Is this that much less expensive or something?

Have you never heard of the 3G before? It's notoriously reliable, powerful, & available in stock form. Not so much any of those in modified form.

Even when I restore this Bronco with the Explorer engine and transmission...

This '75 that I rebuilt for a friend may interest you.

1975 Ford Bronco pictures, photos, videos, and sounds | SuperMotors.net

1975 Ford Bronco photos, pictures, videos, and sounds — 673 photos documented since 2003 on the SuperMotors vehicle registry.

www.supermotors.net

...everything I remove will go onto. ...the old body from my '72 will likely go onto it.

Sounds like you could save yourself a lot of time, money, & effort by simply leaving the '72 parts on the '72, and building the '77 frame with the newer parts.

I've always wanted to learn to weld...

I highly recommend buying a GOOD welding machine that knows how to weld - then you only have to learn how to operate the machine, which is MUCH easier than learning how to weld. I bought the same one that many pros use (a MillerMatic 211), and it makes me look like a better welder than I am.

 

[ba123]

Count all the wires going to your 1-wire alternator. Then count what's shown in the pic of the 3G harness - not at the alternator end, but at the truck end. There's 1 big wire going to the starter relay's B+ post, and 1 small wire going to the instrument cluster. So a standard 3G is a 2-wire alternator. Are you in such a rush that you can't connect 2 wires? You only have time for 1?

Steve, I literally have just one wire.

The power cable from the alt to the battery is all I have.

Literally ONE wire.

https://www.summitracing.com/parts/...lFOmv8_UxhKQPxVa0fUSvmoySrOwnIzuGbdeK7Q5bJ5KD

You're right though, nothing wrong with 2...but just reading this whole thread it seemed like a lot more than connecting 2 wires. Was a headache just glancing over it.

 

[Steve83]

Literally ONE wire.

OK, but I've read a few threads about people having problems from 3Gs converted to 1-wire VR draining the battery & overheating the alt. I've never heard of malfunctions from Ford 3Gs wired the way they should be, even on other vehicles of other brands.

...this whole thread it seemed like a lot more than connecting 2 wires.

Yes, he was overcomplicating it. With a good used 3G harness, it's PnP other than splicing the LG/R wire together.

 

[dmoses42]

It's very easy to add the frame tab using a scrap of Copper tubing, some solder, and a propane torch.

This is what I was curious about. Should be easy enough.