Non Standard 3g Alternator Upgrade?

[horseballz]

OK Folks,
Here's what I'm thinking. I hope you can smell what I'm steppin' in! I won't bore youse guys with every detail, but want you to understand why I'm going where I am going. My plan is to install a 3G alternator, but instead of the normal way, make the charging "system/loop" separate from the main wiring harness and not worry about retaining the original gauge, etc. operation, or even adapting it or it's wiring "into" the existing harness. I mean "HECK" it only requires a sensing wire, charge wire and key on power to "excite" it for operation!

A) Last week a crappy Scott Drake ignition switch crapped out and in the process of generally exploding, dead shorted the main "Hot" wire feed from the battery to the switch allowing the "MAGIC SMOKE" to escape from under the dash! Be very aware that these switches are absolute junk and should be avoided like the plague!

1) Upon just installing a new switch, all seemed to function but with a fairly high amperage draw. as evidenced by the little three wire plug near the puny original alternator getting pretty hot fairly quickly. Funny thing is that my "ALT" gauge actually showed some movement which it has never done before (just barely in the past) and this was my first clue that something was shorting!
2) Upon inspection, I discovered that the main feed wire, from the starter solenoid (Black w/Yellow stripe on most diagrams for 68) to the ignition switch (Yellow in most diagrams) had severely melted insulation and some wire exposed.
3) After poring over diagrams and comparing to my "bone stock, original" wiring, I determined that there is at least one junction/splice of several wires in the midst of the under dash portion of the wiring harness. Depending on which diagram you look at, there may or may not also be some sort of splice in the under hood (called the headlight harness) portion of the harness.
​

B) I removed the instrument cluster, etc, etc, etc. and unplugged the under dash from the headlight harness and began un-taping the harness from that end, until I got to the junction/splice and a few inches beyond.

1) This junction/splice is four wires: the Black/Yellow from the solenoid, Black/Orange constant power to the light switch, Black/Yellow continuing on to the constant power section of the fuse box and the solid Yellow to feed the ignition switch.
2) I then continued to un-tape the harness to the branch off to the ignition switch.
3) What I found was that the only wires compromised and/or heat damaged (melted insulation) were the Black/Yellow from the solenoid and the Yellow to the ignition switch. Even though the melted ones were slightly "stuck" to the wires adjacent to them, none of the others actually got melted.
4) I decided my best course would be to bypass/replace that Black/Yellow under the hood, along with the melted connector to the under dash harness and replace the Yellow from the "junction" to ignition switch. I neatly and nicely soldered and shrink wrapped a new junction and retaped the harness and plugged all back in for testing.
​

C) Before starting the car, I first turned on the ignition switch and tested amperage draw at the battery +positive and found no drastic draw.

1) All gauges, accessories and lights worked normally.​

D) Upon starting the car, the "ALT" gauge pegged to max and in a few seconds began to smoke. I turned the car off and quickly disconnected the battery. No other damage occurred, other than the likely demise of the "ALT" gauge.

1) This inferred several things:

a) There is likely another "junction/splice" (possibly intentional or possibly a short from the melted Black/Yellow wire) somewhere, likely in the under hood headlight harness.
b) This other junction is either a sensor wire (no longer connected) that was "sensing" through the ALT gauge or in the convoluted scheme that Ford used to incorporate this nearly useless gauge, the "charging" was actually going through the ALT gauge!
c) If the charging system and all of it's sensing and monitoing were removed from the harness, all would be well and function for my purposes!
​

Sooooo, after all that, back to my original 3G topic. It seems that doing the 3G install as a separate system should not cause any issues? I realize that the best solution would be all new harnesses and wiring, but I afraid they would likely be made in similar factories in "CHINESIAWANOREANAMPAN" as made the crappy switch that caused this night mare in the first place! Not to mention the price of around a Grand ($1000) by the time all is said and done.

As it is, if I disconnect the alternator, all else seems to function correctly with not any dramatic amperage draw, except no charging while running. I have already, in the past, removed all accessory and auxiliary power from the ignition switch to be powered through a separately fused and powered relay.
From what I can gather, all that should be required is:

A) A nice, heavy #6 or larger wire from the B+ terminal of the 3G to the battery side of the starter solenoid.
B) A #14, or so wire from the "A" terminal of the 3G to a sensing location of my choice. (MAD author http://www.madelectrical.com/index.shtml suggests remote sensing at the point of highest current draw as opposed to sensing at the battery)
C) A short jumper wire from the "S" terminal of the 3G to the small plug on the alternator.
D) A #14 or so wire from the "I" terminal of the 3G to a key on power source.
​

Please correct me if there is some flaw in my thinking and/or plan.

Thanks 4 Your Patience,
Gene

 

[horseballz]

Oh, a couple more questions that I forgot:

A) What year and engine Taurus is the best/easiest for a swap onto a small block? My current mounting is the bolt through to the head is on the top and adjuster arm on the bottom. Also need to think about my V-Belt pulley interchanging properly?
B) I notice when looking at pics on "Rock Auto" that some Taurus alternators only have a two-pin connector, in addition to the "B+" lug and "ground" lug. Does this mean that the jump between the "S" terminal and the extra little plug is already done internally, or..........?

Thanks,
Gene​

 

[tos]

Could it be that you welded the switches in the voltage regulator when this first meltdown occurred? I too have had issues with Scott Drake parts. I installed all new harnesses (Painless) (or rather Painful) and a voltage regulator from Scott Drake I believe? That regulator seemed to work properly but kept getting so hot I could barley touch it and smelt like burning wires. I finally fixed it though by pulling it off and giving it a couple taps with a sledge hammer and then installing it in the garbage can. I then put my old original back on and problem solved.

 

[horseballz]

That's a possibility I hadn't considered, although, I think mine is one of the more modern "electronic" units with no mechanical switches or points. Definitely something additional for me to check. Either way, I kind of have been planning to upgrade the alternator, given that the original has only just barely kept up, especially when using the air conditioning and I've also been considering going to an electric fan here in "HOT" Las Vegas. Day before yesterday it was 118 on my patio!
Thanks,
Gene

 

[tos]

Yeah, You probly know about these but when I was stationed in Phoenix we had a water misting system on our back patio to make it bearable to sit outside.

 

[horseballz]

Yeah, bearable, but I prefer being in my air conditioned studio playing my guitar and writing songs!
If you look in the upper right corner of this page, you should see an envelope shaped icon. if you click that, you should see the message I sent you. This website software calls them "conversations" as apposed to "PM'"s or "Private Messages". I tried to attach the png file, and even though it tells that png is okay, up to 14.6 mb, it tells me that the 250 kb file is too big!

Thanks Again,
Gene

 

[jrichker]

Since all my experience is with Fox body Mustangs 86-93, all I can speak to is the 3G installation., With that in mind, here is what I have...

Tech note courtsey of SwAmPf0x:
How to wire a 3G in an 85 or earlier Mustang
cut and paste from an old post of mine...

There are 4 wires to the voltage regulator, cut the plug off the regulator, extend the 2 wires used to the alt and cap off the other 2

The F will not be used.
The I will not be used.
The S will go to the 3G
The A will go to the 3G

wiring on the 3g side

The Big post on the back goes to the solenoid, same side as the battery, a fuse is recommended on this wire, also up the wire size to 4ga minimum

Now for the 3 wire plug...wires A,S,I

A goes to A from the old external regulator
S goes to the stator connector on the 3G
I goes to S from the old external regulator

Add an additional 4 gauge ground wire form the engine block to the body ground point that the negative battery cable attaches to.

 

[horseballz]

Thank You jrichker,
What I'm desperately trying to determine is how to properly use the alternator as a "stand alone" unit, NOT utilizing any of the existing wiring for any of it's function. It appears that all of my problems are related to the goofy setup that Ford originally used for charging and monitoring of that charging, along with possible damage to that portion of the system.

I'm hoping to avoid totally dismantling much of my car to completely rewire it when all that is likely needed is a few seemingly simple wiring repairs and/or upgrades. I simply need the info to proceed!

Thanks Again,
Gene

 

[Rusty67]

The diagram jrichker posted should be all you need.it doesn't piggy back on anything existing as lon as you have a key on relay to use. Otherwise you do need to tie into the ignition switch for the green/red wire. I've installed several 3gs, very easy to do.

 

[Noobz347]

Thank You jrichker,
What I'm desperately trying to determine is how to properly use the alternator as a "stand alone" unit, NOT utilizing any of the existing wiring for any of it's function. It appears that all of my problems are related to the goofy setup that Ford originally used for charging and monitoring of that charging, along with possible damage to that portion of the system.

I'm hoping to avoid totally dismantling much of my car to completely rewire it when all that is likely needed is a few seemingly simple wiring repairs and/or upgrades. I simply need the info to proceed!

Thanks Again,
Gene

If you have wire that is damaged beyond what is shown in the diagram then no alternator is going to fix what ails it. This setup bypasses the stock charging wires with the large gauge wire running to the starter solenoid. Your existing charge wiring is not used and it's not really a good idea to parallel the stock wiring with the new large charge wire.

That said:

If your stock wiring is damaged to the point where it might cause a short by touching other components, then it needs to be removed. However much digging that is necessary is just that.... necessary. The stock wiring can and will still pick up a charge at any point in your body wiring, where wires meet.

If the stock wiring shows physical damage... You need to remove it. It should not require much dismantling.

 

[Rusty67]

Noobz makes a great point. Make sure you pull the old charging system wiring or you could have yourself an electrical fire from a short. Also, clean up any damaged wiring in the harness for the same reason.

 

[horseballz]

All damaged wires either removed and/or fully disconnected along with voltage regulator. Any original wiring not in use, but left in place, reads NO continuity to ground or hot! It also reds 0.00 Volts when all is powered up. Please bear in mind that little to no current draw goes through the main harness, as every bit of load has long ago been relegated/converted to being powered through relays. All the main system provides is the switching current for the relays. This "SAVE" is certainly not recommended for electrical novices/dabblers or the faint at heart.

13.97 VDC, at battery, at idle and even higher RPM, with all AC, lights, wipers accessories on. Lights do not dim and turn signals do not slow down at idle!
Still reads 13.97 VDC at idle, with everything turned off. This 130 AMP alternator really kicks a$$ at doing it's job and keeping up! It only gives a belt chirp/short squeal at a quick rev in the first few seconds after start up. Not a peep after that or under full operating load.
12.75 VDC, with car turned off.
0.042 AMPS draw between disconnected +Positive battery cable and battery +Positive. This is the memory "Key Off" draw of the fairly low powered Pioneer stereo. When I disconnect this lead to the stereo, draw goes to 0.00 AMPS.
All measurements made with a good Fluke 179 meter.

Thanx 4 All Help & Thoughts,
Gene