Close



Results 1 to 19 of 19
  1. #1

    Default what alternator options

    I am thinking a 95-100 alternator will be fine for my 86, not a lot of accessories, is there such an alternator that will bolt right in without changing up wiring?

    Or do I need to do a 3g upgrade to get to 100 amp alt.

    Thanks

    Todd

  2. #2
    FEP Member
    Join Date
    Dec 2016
    Location
    Grand Rapids, MI
    Posts
    301

    Default

    The alternator in my '91 Crown Vic is 100 amps and looks like it is the same case as the alternator for your car. It is however externally regulated so there would be some minor wiring work.
    '89 XR-7 5 Speed
    '95 SC 5 Speed
    '91 Crown Vic P72 351W
    '95 Saturn SW2
    '85 Ford LTD Squire

  3. #3

    Default

    Considering the stock wiring uses a single 10 gauge wire which is only good for 40 amps, I wouldnt recommend not upgrading wiring. Its pretty common for the connector to melt and short out as is.

    Also, of you do not upgrade the wiring, other then the car maybe burning to the ground, the stock fuseable link will either melt or blow. If it doesn't, then you didn't need to do the upgrade to begin with.

    Good luck, either way. If you like the car, I'd probably upgrade the wires...
    2 1986 cougars (both 4 eyed and 5.0)
    1 1987 cougar

  4. #4
    FEP User
    Join Date
    Oct 2017
    Location
    south-central WY
    Posts
    66

    Default

    Don't even think about putting a gen2 alternator in your car. If you have one on there, replace it with a gen3 asap. Then give the old one to your worst enemy.

  5. #5

    Default

    I used a 3g alternator from a v6 sn95. Took about 45 mins to install and solder the connections.
    My Previous Stangs:
    86 GT, t-tops, 5 speed.
    87 GT, sunroof, 5 speed.
    88 GT, sunroof, 5 speed.
    89 LX, Sunroof, Roller (project)
    90 Coupe, LX, 2.3, 5 speed.

  6. #6

    Default

    Someone who has done an 86, post up a wiring diagram with a few pictures please...... or if you know of an old link to reference.

    people tell me all the time it’s one thing to say something is easy (for me) and entirely another for them to do anything but hire me to do it (which is never my intention....)

    just a thought on helpfulness


    I bought a butane solder pencil kit at Lowe’s that I really like, btw. Works great for soldering and shrinking tubes.

  7. #7

    Default

    AFAIK the numbers on the original alternator on my 1986 indicated it is 60 amps.

    The only upgrade you *might* get away with (and what I did in the 90’s when I had one go out and didn’t know any better admittedly) is take a supercoupe alternator which is 65 amps and reclock it.

    But agreed — I’ve since seen the stock wires melt with a stock alternator before.

  8. #8

    Default

    pretty simple swap.. done this on countless Fox Body cars
    3G from a 94-95 mustang from either a junkyard or Rock Auto
    4 gauge power wire with a weather titie inline 150 amp Buss fuse. You can get this on Ebay for around $35 with the terminal ends already attached. Run it to the + side of the starter solenoid where the battery cable is attached to, not to the post that goes to the starter
    Get the harness from LMR so you can jumper the exiter wire off your 2G plug to the 3G, as the 2G plug is only 2 wires. Makes it plug and play
    https://lmr.com/item/PA-462802A/86-M...onversion-Wire
    do NOT reuse the stock 2G power wires or plug.
    you will need to clearance the stock alternator bracket as the 3G case is larger
    You will need to get a bolt and nut for the top bolt hole on the 3G
    reuse the 2G pulley as the 3G is larger
    Last edited by mikestang63; 09-14-2018 at 07:48 PM.
    1986 GT T Top- stock except for magnaflow cat back
    1990 LX vert- 500hp V3 and all that stuff
    2013 GT- usual bolt ons

  9. #9

    Default

    A larger pulley may be a good thing if you like to run a lot of RPM.

    I kept spinning the bearings out of my 2G when revving my car past 6000.... even with the underdrive setup.

    A smaller (under drive) on the crank and using the (larger / underdrive) stock alternator pulley instead of the smaller (overdrive) one that came with the pulley kit is what I did to solve that.

    The kits make a lot of compromises looking for HP while having near stock charge qualities at idle. It’s fine if the motor is stick but if you start running R’s it has to be tweaked in my experience. Oh and get a bigger CCA battery to carry the lights and stereo and stuff at idle too,....

    if you run R’s a Stock crank with the larger 3G pulley could be a good compromise - maybe. Haven’t tried it. I do know it’s just about mandatory to run near 1:1 on the water pump if you make any amount of power. Mine would not tolerate the slower waterpump
    speed even with a FB169 radiator.

  10. #10

    Default

    Honestly, I noticed almost zero difference when I did my 3g. I have a ton of electronics in the car, plus two dash cams and a hoard or usb chargers. I also have a nearly brand new plug and play 3g set up sitting right here. When my old alt went out, I just replaced it with a stock one. Most charging issues are cause by a bad ground and cable setup.

    Almost every stock plug I've pulled off the alt eother crumbled or was burnt up. Replacing the plug is plenty unless you want to run a high power electric fan or have a big sound system. Otherwise, I doubt you could even tell the difference.
    2 1986 cougars (both 4 eyed and 5.0)
    1 1987 cougar

  11. #11

    Default

    I do have an electric fan from LMR and plan on putting a simple stereo system in it. That is about it.
    will the stock alt run the electric fan? I would think it should.

  12. #12

    Default

    I'd probably upgrade. The simple reason, my Taurus fan used a 10 gauge wire, that's what my stock alt took.
    2 1986 cougars (both 4 eyed and 5.0)
    1 1987 cougar

  13. #13
    FEP Super Member gr79's Avatar
    Join Date
    Jun 2009
    Location
    SE Michigan
    Posts
    3,485

    Default

    For what its worth:
    Was at a pic a part yard today
    Seen a Merkur XR4-TI intact
    90a Bosch small alternator has internal regulator per Rock Auto info 85-89 XR4-TI.
    Name:  merkur engine (2).jpg
Views: 68
Size:  111.7 KB

  14. #14

    Default

    Look at the size of that stock charge wire. Its beautiful.
    2 1986 cougars (both 4 eyed and 5.0)
    1 1987 cougar

  15. #15
    FEP Power Member
    Join Date
    Nov 2007
    Location
    San Mateo, CA
    Posts
    1,477

    Default

    Besides the reliability issue, a few things that would push it to upgrade the wiring and the alternator to the next generation is adding an electric fan. I’m not a big fan of making the alternator upgrade but I think the fan will require it.

    You can always try going to an alternator shop for suggestions.
    Fox Body/3rd Gen MCA Gold Card Judge
    84 SVO 24K miles, 85 Mclaren Capri Vert. 84 GT Turbo Vert.
    88 Mclaren Mustang Vert 20K miles, 89 Mustang LX Sport Vert, 92 GT Vert.
    03 Mach 1 7900 miles, 74 Mustang II, 69 Mustang, 67 Mustang, 14 Mustang CS/GT,
    15 F150 FTX Tuscany, 16 F250 Crewcab, 67 Tbird 47K miles

  16. #16
    FEP Power Member
    Join Date
    Nov 2007
    Location
    San Mateo, CA
    Posts
    1,477

    Default

    Another option,
    135-amp Lestek Alternator with Transistorized Voltage Regulator, was used on some of the ASC Mustangs. I think it may have been used on the SSP cars too. I’m not sure if there were wiring changes.

    Lestek 6542 Baker Blvd., Ft. Worth, Texas 76118 @ 1-800-433-7628
    Fox Body/3rd Gen MCA Gold Card Judge
    84 SVO 24K miles, 85 Mclaren Capri Vert. 84 GT Turbo Vert.
    88 Mclaren Mustang Vert 20K miles, 89 Mustang LX Sport Vert, 92 GT Vert.
    03 Mach 1 7900 miles, 74 Mustang II, 69 Mustang, 67 Mustang, 14 Mustang CS/GT,
    15 F150 FTX Tuscany, 16 F250 Crewcab, 67 Tbird 47K miles

  17. #17
    FEP Super Member gr79's Avatar
    Join Date
    Jun 2009
    Location
    SE Michigan
    Posts
    3,485

    Default

    Big alt needed for say emerg.veh with high ele loads at idle.
    Reg car not so much. Newer cars much more power hungry that 80's cars. 100a+ alt. common

    Upgraded my 79 from the 40a small case 1g to 70 large case 1g back in the 80's.
    Its larger and heavier but works fine. Used in lots of Ford cars and trucks 70's-80's.
    Minor rewiring (alt connector pigtails), longer bracket for adjustment, longer belts. Same pulley.
    Regulator stock Motorcraft GR540B. New pigtail in 2000. Read good for 100a.
    Besides stock equip, 600w stereo amp, fog lights. seat heater.
    Will drop back on the voltmeter a little at idle with full load like cold rainy night with defog, heater blower on.
    Maybe 12v but once moving again, up to 13+. Recharges battery quickly.

    Don't really care for the wire gauge on the pigtails, but no problems to date. They look fine.
    Figure 70a x 13.5= 945w
    Home 120v 14g or 12g stranded wire extension cords current capy are rated well above that.
    Current is current whether ac or dc. 12v dc is 1/10 of 120v ac.
    Just like at home, a larger wire is like a larger water pipe. can carry more less stress and loss.
    Depends on how long it needs to carry high current. A cig lighter has a small power wire.
    Read current determines thickness of wire, voltage the thickness of insulation.
    Battery can absorb only so much current from the alt. Thus small wires. 10a x 12v= 120w.

    Two circuits. Before battery and after. Battery is the power bank for the car. Alt charges it.
    Car battery wont take a 50a charge, say with a 120v battery charger, very long. Boils water out.
    More like 10a dc or 2a dc trickle.
    A low normal sized car battery prob only needs 20-40a dc to charge when driving. 260-540w.
    Small stock gauge wire can do this. High current will heat the wire up.


    http://www.madelectrical.com/electri...evymain3.shtml
    https://www.onallcylinders.com/2015/...ut-alternator/

    Bigger wire? Can use regular wire spade connectors alt and reg ends directly on terminals instead of smaller wire pigtails.
    I do. Car electrical is car electrical. Harness' have advantage of connector protection around the spade.
    Old pigtail connector covers may transfer over.

    Small case 70a 1g alt are available. Same connectors as 40a.

  18. #18

    Default

    Heres the thing though. If the stock wire (rated at 40 amps) is fine, then what's wrong with a 60 amp alt? What's the point if the upgrade if you keep the stock sized wire? Other then burning the car to the ground of course.
    2 1986 cougars (both 4 eyed and 5.0)
    1 1987 cougar

  19. #19

    Default

    Quote Originally Posted by Haystack View Post
    Heres the thing though. If the stock wire (rated at 40 amps) is fine, then what's wrong with a 60 amp alt? What's the point if the upgrade if you keep the stock sized wire? Other then burning the car to the ground of course.
    Very accurate!
    -- James

    "Trigger" - 86 Mustang GT - Black with red interior. 5.0 T5 built as Z. Original motor ~1/2 million miles. 18 yr daily, 7 a toy
    "Silver" - 85 Mustang Saleen 1985-0006? (Lol) Rare 1E silver / charcoal interior. Mystery. Current project roller, tons of Saleen pedigree

    Also in the stable - 1986 Mustang GT Convertible. Black/Black/Black conversion. 93 leather. VM1 ECU. T5Z

    past foxes -
    1989 Mustang LX Sport 5.0 AOD white/tan black top.
    Wife also had a 1987 Thunderbird Turbo Coupe in the 90's.

    I'm a four eyed pride supporter, are you? Become one today!

Posting Permissions

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