3G Alternator Install: A How To

Discussion in 'Fox 5.0 Mustang Tech' started by Roland69, Jul 3, 2006.

  1. Someone please correct me if I'm wrong here.

    If one is using a pigtail off a 3G alternator (PIC #1) with the self-contained stator wire (Red Arrow), wouldn't one then just eliminate the SMALLEST wire from off the car's rectifier plug wiring harness (PIC #2) ??

    PIC #1


    PIC #2

  2. Katmandu: Yes.
  3. if i cut the white/black wire and connect it to another wire with a 1/4female will that work instead of doing the Y splitter?
  4. Nice write up Roland.
  5. Yes.

    The Y like Jrichker does is for convenience [in the event of reverting back to a stock alternator].

    Doing a Y is just as easy, unless one is using solderless connections.

    If you use a solderless connector on the cut stator wire and your new jumper wire (instead of soldering the jumper wire to the stator wire), you could put a complimentary connector on the rectifier-side stator-remnant. That way, if you need to reconnect the OEM stator circuit back together, you can just plug the two connectors together.
  6. :nice: thanks thats the way i did. It seems like the guy who use to own the car before me had done the swap or messed with the wires since the white/black and the orange/black wire had some heat tape on them.

    its working good. Im just gonna add the 4ga ground and check the voltage :hail2:
  7. Need some help! :bang:

    I just did the 3G upgrade and the voltage gauge is showing discharge and the battery light is lit up.

    I used the original 3G voltage regulator pigtail (see my pics above).

    I totally eliminated the factory rectifier wire and replaced it with a 4 Gauge wire to the starter relay.

    The original 3G voltage regulator pigtail has a self-contained white stator wire that loops back into where the spade connector goes. There's (2) other wires (green and yellow). The factory harness has (3) wires. Green, Yellow and white. I spliced in the green and yellow wires and cut the end off the white wire and taped it off.

    I'm thinking I should have spliced the white (looped) wire into one of the white wires from the factory harness. ??? Doesn't the stator need a 12V charge from somewhere ?? :shrug:
  8. Katmandu, you should have been fine doing the looping. The only non-looped regulator wire is the excite wire (seeing 12 volts through a resistance circuit).

    Are you sure the alternator is good?
  9. Which wire is the exite wire in my set up ?

    Wear do the white wires (in both) in the car's harness attach to at the other end (opposite the alternator that is) ?

    Also, I'm going to pull the alternator and have it tested tomorrow.
  10. I finally was able to get an order into Ford Fuel Injection (RJM Injection Tech) for my Alt Harness! It really looks to simplify the Installation as you only have to tap the Green/Red Wire!
  11. Lt Green/red.

    The white stator wires just makes a big loop from the rec to the reg (or reg to stator terminal). There is no 'other end' to it.
  12. So your saying it goes from the rectifier harness back through the voltage regulator harness ?
  13. So is the Excite wire the YELLOW wire then ??

  14. No, it's lg/red (on the right side of your diagram. It goes through the "Optional Instrument Cluster Charge Lamp" and to an ignition source. The excite wire is labeled I.

    Yellow is the sense circuit (labeled A). It sees battery voltage. It's connected to the battery-end of the charge cable (or to the alternator's charge-stud if the charge cable is in impeccable shape).
  15. I believe this is how the YELLOW wire should be mounted up when using the original 3G voltage regulator pigtail.

  16. Hidden in the harness there is a fuse link inline with the yellow wire. It is supposed to blow if the regulator shorts out, so it doesn't make an electrical fire. You can run the yellow wire directly to the alternator output, but that by passes the fuse link.

    The other option is to use a fuse or fuse link inline with the yellow wire. I don't have a spec for the current rating for the fuse or fuse link, but I suspect that it is less than 10 amps.
  17. The fusible link on the sense circuit is an 18 AWG as I recall.

    Alternatively, 94-95's use a 20 amp fuse on this wire.
  18. Well, I got it to work finally! :D

    I routed the yellow wire directly to the alternator output (rectifier post) along with the 4 gauge wire.

    The reason my setup didn't work initially was because I FORGOT I cut the other end of the wire off (that connected to the starter relay) and taped them off. I eliminated the car's original rectifier (2-black, 1-white) wires in lieu of the 4 guage wiring. Since the voltage regulator's yellow wire ties INTO this harness, it had NO POWER going to it! DUH!! :bang: :nonono: :mad:

    But all's good now! :nice:

    Just need to make time to stick fuses in the wiring next.
  19. whats the difference between the 3G, and the PowerMaster 140amp alternator, I have the PowerMaster 140amp with one wire hook up, like a 20 min install, should I be running a fuse in between the alternator and the battery, doesn't say in the instructions