Close



Results 1 to 9 of 9
  1. #1
    FEP Member 4eyed85gt1's Avatar
    Join Date
    Oct 2010
    Location
    Lakeside, California
    Posts
    439

    Default 3g alternator upgrade

    How hard is it to do the 3g alternator upgrade on an 85 foxbody....and is the sve set up from lmr a good one...any feedback or tips would be appreciated..thanks
    85 ford mustang gt 5.0 h.o.5 spd
    68 chevy nova SS 350 (slightly modded)
    92 ford ranger prerunner

  2. #2
    84 Cougar, 88 HO with 700DP, Edelbrock RPM intake, 1.7 RRs, shorty's and SS exh, T-5, KC clutch, Hurst pro billet, line loc, 8.8, 4.10s, suspension mods....blah, blah,blah.

    71 Comet, 289, Liberty TL, 9", 6.00s, 11.9x @ 112.... blah, blah, blah.

  3. #3
    FEP Power Member gmatt's Avatar
    Join Date
    Jul 2009
    Location
    Chicago, south subs
    Posts
    1,723

    Default

    The kit from LMR is pretty much plug-n-play. I put it on my Fairmont. I think it came from PA Performance. There's a how-to video link on their site. The nice thing about kit is that it includes a replacement for the stock voltage regulator to keep the dash light from coming on.
    Last edited by gmatt; 10-21-2018 at 01:04 PM.

  4. #4

    Default

    I didn't think the swap was too bad, just used wiring diagrams from google (the first pic in quickshift's link above). Didn't use the kit. Picked up a used 130A alternator from the junkyard and rebuilt it. Ordered battery cables, regulator pigtail and a fuse block online. Trimmed the alternator bracket and it was all pretty much a bolt-in deal.

    In progress shot of my wiring:
    Thomas

    1985 Mustang GT - Build Thread
    347 (10.5CR, AFR 185's, PP Crosswind, Comp Custom Cam, Holley SA "670"), T-5, 8.8 w/3.55's, MM SFC's, T/A, PHB, LCA's, STB, KMB, Bilsteins, MM/H&R Springs, SN95 5-Lug, Cobra Brakes, '04 Mach 1 Steering Rack

  5. #5
    FEP Member 4eyed85gt1's Avatar
    Join Date
    Oct 2010
    Location
    Lakeside, California
    Posts
    439

    Default

    Thanks alot....before I continue my stock piling of maximum motorsports suspension parts...I need to get that kit and fix that problem....thanks again.
    85 ford mustang gt 5.0 h.o.5 spd
    68 chevy nova SS 350 (slightly modded)
    92 ford ranger prerunner

  6. #6

    Default

    Quote Originally Posted by 85MUSTANGTGT View Post
    I didn't think the swap was too bad, just used wiring diagrams from google (the first pic in quickshift's link above). Didn't use the kit. Picked up a used 130A alternator from the junkyard and rebuilt it. Ordered battery cables, regulator pigtail and a fuse block online. Trimmed the alternator bracket and it was all pretty much a bolt-in deal.

    In progress shot of my wiring:
    Exactly.

    I think you obly really need to splice one wire abd run the new charging cable. I really don't understand why people make such a big deal about it and insist on ordering a $400 kit.
    2 1986 cougars (both 4 eyed and 5.0)
    1 1987 cougar

  7. #7

    Default

    Yup, pretty much. Splice the green wire from the original external regulator to the green wire on the 3g pigtail. Trim off and insulate the other factory wires. Run 3g pigtail yellow wire to a constant 12v source (ran mine straight to + battery terminal) and loop white wire to field terminal on alternator. Connect electric choke wire to white wire if needed. Then make up a new fused charge cable, think I used 4 ga. That's pretty much it for the wiring.
    Thomas

    1985 Mustang GT - Build Thread
    347 (10.5CR, AFR 185's, PP Crosswind, Comp Custom Cam, Holley SA "670"), T-5, 8.8 w/3.55's, MM SFC's, T/A, PHB, LCA's, STB, KMB, Bilsteins, MM/H&R Springs, SN95 5-Lug, Cobra Brakes, '04 Mach 1 Steering Rack

  8. #8
    New User ID89GT's Avatar
    Join Date
    Feb 2011
    Location
    Spokane Valley, WA
    Posts
    37

    Default

    I did it on my 85. Its a pretty straightforward swap. I eliminated my external regulator and just wired it direct. The green and red wire for the 3g plug goes to the green wire on the voltage regulator. Then the yellow wire from the 3g plug just hooks up to the yellow wire at the voltage regulator. Tape off the old power cable and run a new 4 gauge wire with inline fuse. And don't forget to add a new 4 gauge ground cable from the engine to body also.
    1985 Mustang GT TTOP

  9. #9
    FEP Senior Member 83gt351w's Avatar
    Join Date
    Nov 2014
    Location
    Grand Rapids, Mi
    Posts
    609

    Default

    On mine, I got rid of my voltage regulator, seems redundant having two. The wire that requires 12v constant, loop it to the main cable on the alternator. No sense in running it to the battery. A lot cleaner install this way.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •