Electrical 85 1g to 3g conversion HELP!

[Some guy up north]

Hey folks! I'm currently in the process of converting my 85 mustang gt from 1g to 3g using the pa performance kit. I don't think i really needed to buy this kit, But i did in order to keep the dummy light in the dash functional. I'm mostly done the swap however I am hung up on a thing or two. To start I'll mention that that the car started life as CFI but now sports a carburetor. I bought the car not running with much of it's wiring jerry-rigged or removed, so I don't have much of a reference here.

first this orange/blue wire that I found dangling about that leads to the "f" terminal on the new external regulator. This is what I believe to be the field wire and should connect to the green wire on the 3g harness, I'm I correct on this?

second, this green/red wire connects to the "s" terminal on the external regulator and seems to lead to another connector that doesn't plug into anything. I'm assuming I'm missing some of the wiring here or that it's for the original CFI harness. What should this wire connect to and what does it do? Do I leave it alone and unplugged? I might be beating a dead horse here but I can't seem to find what I'm looking for online any help is appreciated. Thank you!

 

[Some guy up north]

I have the wiring connecting to the external voltage regulator, it's where the wires go to from there that I'm missing

the "f" terminal coming off of my regulator (orange/blue wire) I believe went to the 1g harness but can't confirm as I don't have the harness. Is this correct? The green/red wire "s" on the external regulator leads down to the connector seen in the middle of the picture. I don't have this harness either, and don't even know what it went to. The yellow wire pictured, "a" on the external regulator is the only one going to anything. It leads to a bundle of fused links that then connects to a thicker yellow wire that goes through the fire wall into it's own grommet.

 

[Blown88GT]

I have something on this conversion that I found 20+ years ago.
I copied it from my old website section, 3G, 130A ALTERNATOR UPGRADE
Hope this helps.

Alternator Connections for Other Years:

On your 84 external voltage regulator, you have the following:
F, S, A, I

Unplug the wiring harness going into the external voltage regulator. Either splice into with your new wire or make a blade connector that will go into the old wiring harness. You will need to tap into two of those wires:
The F will not be used.
The S will go directly to the I on the 3G. The A will go directly to the A on the 3G. The I will not be used.

Looking at it from the 3G viewpoint:

The BAT goes to the inline fuse.
The stator connector goes to the S connector on the 3G.
The A connector goes to the A wire on the old wiring harness.
The S connector goes to the stator connector on the back of the 3G.
The I connector goes to the S wire on the old wiring harness.

 

[Some guy up north]

This is great info! So with it wired in this fashion it essentially bypasses the external regulator correct? Seems the replacement pa performance regulator was a waste buying.

 

[Blown88GT]

The 3G has an internal fan instead of the external ones of the earlier ones. It's much more efficient, therefore, more power output.

 

[Exrace89GT]

First off, no external regulator is used on a 3G alternator. There is an excellent article in the February 2019 issue of Hot Rod magazine. I think it is available on line. There are only two wires that need to be hooked up. One is the main charge wire and the other is the idiot light (exciter) wire. If you can’t find the article let me know and I’ll try and post it here.

 

[Kevnic]

I am upgrading to a new 100? Amp alternator on my 84 and I am going with jegs 55510132 . I would go boneyard, but want to keep it on a quick turnaround as I don’t have time to go to the junkyard.

I need a wiring kit to go with it, is it something I can buy online or do I need to get that from a boneyard? I know it is internal reg vs my outdated regulator, what plugs would I need? Thanks guys

 

[jrichker]

@Kevnic

3G install into an 85 or earlier Mustang:

I would recommend the addition of a 2 amp fuse on the Light Green/Red wire that goes to the switched ignition.
I would use a maximum of 125 amp fuse for the output wire that connects to the starter solenoid.

The prices below have changed, but this is a list of what you need to do your own wiring.
For a 120 amp circuit breaker see https://www.delcity.net/store/Hi!Amp-Circuit-Breakers/p_167861

Fuse holder from local NAPA dealer - Item#: BK 7821143 Price: $12.99
Product Features: Thermal Plastic Holder For AMG Type Fuse Rated From 100 To 300 amp.

I would use a maximum of 120-125 amp fuse for the output wire that connects to the starter solenoid. Fuses are slow blow so it would pass 130 amps for a continuous runtime without blowing.

See WWW.partsexpress.com for the fuse & fuse holder.
Fuse @ $3.90 each (need one) http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=071-952

Fuse holder @ $5.80 each (need one). http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=263-630

Check on the wire prices, they tend to change often. Copper is an expensive commodity these days.

*4 gauge black wire for needed supplemental ground @ about $1.95 a foot (use string to lay out routing & determine length).

4 gauge red wire @ about $1.95 a foot (use string to lay out routing & determine length).

4 gauge ring crimp terminals (package of 5) $3.25.

3/4 “ Black heat shrink tubing, 4ft length, $3.56

3/4 “ Red heat shrink tubing, 4ft length, $3.56

Pre-fab 4 gauge cables with lugs already on the ends are available in most auto parts stores. Look for the starter switch to starter cables.

*Keep in mind that you are not just trying to charge the battery, but power the lights, A/C, wipers, radio, etc. Each one uses chassis ground as the return path to its power source. Without the extra ground, the current flow is from the engine block to the starter power ground and back to the battery. The current must then flow through the small 10 gauge ground pigtail to reach the chassis. The secondary power ground for the alternator is a 10 gauge ground strap from the back of the intake manifold to the chassis. It is often damaged or completely missing. The 4 gauge ground wire will cost less than $5 and it will insure that there is a low resistance path for the alternator's output.