Replacing 2g Alternator 87 Mustang Gt Need Help!!

Assassin 5.0

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Dec 19, 2014
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couple of days ago when i started up my 87 5.0 i noticed that the voltage had spiked and sat at almost 17-18 volts on the meter until i turned the headlights i heard some clicking under the dash and then the voltage dropped to 8 volts and stayed there..... needless to say i have an alternator / voltage regualator problem.

heres the issue... removed the alternator from the car today and ran into this issue. i cannot remove this plug and there seems to be no way to get it out. from pictures around the net it is the rectifier plug but i need someone to tell me whats going on here because unless im missing something this plug looks like it does not come out..does it need to be cut? there are no clips or spade to push to even unclip it.. ..please help thanks
Photo Dec 18, 5 24 40 PM.jpg
Photo Dec 18, 5 24 46 PM.jpg
 
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It is not uncommon for the pigtail to have the clips broken off or to overheat and get stuck on the alternator. If you replace the alternator with a new or remanufactured unit, it should come with a new pigtail connector. Cut the old pigtail off, strip the wires, put on shrink wrap tubing on the wires and SOLDER the new pigtail on. Don't crimp, don't wrap, don't do anything else but solder the wiring.


I suggest that you check the fuse link for the alternator prior to replacing the alternator. Check to see that you see battery voltage at the alternator and at the green wire on the starter solenoid. Good 12 volts, good fuse link - in most cases.

64326d1287785504-fusible-link-burned-up-need-help-87-93-5.0-mustang-fuse-links.gif



Alternately, you can do a 3G alternator upgrade and get a better 130 amp alternator and some new wiring for just a little more cost than the replacement 2G alternator.

See http://www.stangnet.com/mustang-forums/threads/3g-alternator-install-a-how-to.646825/#post-6673702
 
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It looks like someone else already crimped on new wiring. That's not factory wiring/plug.

That was my initial observation when I first looked at it that someone may have installed a new alternator previously..what threw me off was that every 2g alternator I've seen or looked up for reference had a removal rectifier plug...this plug seems to be permanently installed and unremovable unless cut and re-soldered...I thought I might be able to reference the alternator brand but there aren't even any identification numbers or names on the alternator to reference...I guess my next move from here will be to try and change out the voltage regulator since that's the cheapest method of elimination without cutting the wires out..I have considered the 3G alternator but I'd like to find out what's really going on here before I spend the money on a brand-new alternator. I'll keep everyone posted once I get the new regulator.
 
I would get a 3g and be done with it. You will be spending money on a 2g which are barely adequate for a stock mustang and the wiring are fire hazards. Total upgrade is less than $100 for a junkyard alt 94/95 mustang gt alternator and wiring kit off Ebay. Clearance the bracket a little for the larger 3g case, use the wiring from the new kit, swap the pulley and you are done. If you want to get rid of the rectifier plug altogether, get a 1 wire alternator- they are about $200 new from PA performance.
 
As far as the 2g alternators coming with a new plug, is that something new, or is it special to these alternators? Once upon a time, I tested every starter and alternator that came in our parts place. And I only remember a few imports (with a changed design) and a GM model or two with extra parts in the box.
 
As far as the 2g alternators coming with a new plug, is that something new, or is it special to these alternators? Once upon a time, I tested every starter and alternator that came in our parts place. And I only remember a few imports (with a changed design) and a GM model or two with extra parts in the box.
Just like everything else, some rebuilders do the right thing and some cheap out whenever they can. Eliminating the new pigtail from the kit saves them a few $.
The old design was pretty sorry, since the push on connectors get hot and lose their grip. When they do, more heat generated by the high resistance connection makes it worst and it becomes a vicious cycle.
 
so i havent had a chance just as yet to work on the car since last post but i do have a question about the inline fusable link. based on the event that happen, it is more than likely that the fusable link is probably burnt and needs to be replace which i plan on doing regardless..my question is can i replace this with an inline maxi or megafuse or ANL fuse set-up? or is it important to keep it a fusable link? assuming i decide to just keep the 2g alternaor set up?
 
Fabric wrapped wiring is pretty old. I wouldn't be surprised if that Alt wasn't sourced from an older Ford model and just spliced in.


If it was my car, i'd head to a boneyard and snip off the wiring from a 80's/90's ford with same alt and solder it in place with heat shrink. I'd grab a stator plug off a 90's-later ford and then do a 3G or 6G conversion and run a large gauge power wire.
 
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You can use a 65 amp fuse, but be sure that it uses screw or bolt connections to the fuse. The push on tabs are not the best solution for a high current connection.

Fuse link material is available at most good auto parts stores. There may even be a fuse link already made up specifically for your car. Just be sure to solder the connection and cover it with heat shrink tubing.

Heat shrink tubing is available at Radio Shack or other electronics supply stores.

See video for help on soldering and heat shrinking wiring.

View: http://youtu.be/uaYdCRjDr4A
 
Even Ace usually has shrink tube, as do most good parts stores. If you really like the stuff, HFT has big packages of the stuff in varied sizes and colors!

The best electrical tape I have seen is some self adhesive, self sticking and self curing rubber stuff from Ace. The roll is separated by a layer of blue plastic that you peel as you go, and when the tape is wrapped around itself, it produces a waterproof bond that is not easily affected by heat. It also makes tool grips easier than the tool dip method.
 
S
I did a G6 swap in my '87 a while back and I couldn't be happier with it. Easy to find, very cheap, easy to install (no notching the bracket, no stator wire, no changing the pulley, etc), and as reliable as a cast-iron skillet.

http://www.stangnet.com/mustang-forums/threads/6c-alternator-swap-for-79-93-5-0.866607/

So, your saying if I source a 6g alternator from a 04 v6 mustang, this will be a direct and complete bolt on to my 87 GT, pulley and all, with no grinding of the bracket needed? id rather prefer to do that then getting a 3G and grind and the bracket.
 
S


So, your saying if I source a 6g alternator from a 04 v6 mustang, this will be a direct and complete bolt on to my 87 GT, pulley and all, with no grinding of the bracket needed? id rather prefer to do that then getting a 3G and grind and the bracket.
Grinding the bracket is no big deal unless you don't have the tools to do it. Dremel tool, drill or die grinder and a rotary file are what you need.
The main thing is to do the power wiring upgrade correctly. Cheap out or cut corners and use the stock power wire and you are asking for trouble. No matter what high output alternator you chose, this is a must do it right item.
 
S

So, your saying if I source a 6g alternator from a 04 v6 mustang, this will be a direct and complete bolt on to my 87 GT, pulley and all, with no grinding of the bracket needed? id rather prefer to do that then getting a 3G and grind and the bracket.

Well, it's simpler if you just review my linked post, but I'm saying that with the exception of trimming the sleeve (which likely wasn't even necessary) and adding the top bolt, it was a simple bolt-on for me, and the wiring was easy because there's no stator wire like there is on a G3.

I also included a very informative link that details the differences between the G3 and G6 units. If there's a good reason to go with a G3 over a G6, I haven't been able to find it...unless of course you already have a G3 on hand or know where you can get one for next to nothing.

The post I linked you to also has numerous references to the issue of whether or not to uprgade the charging wire, so I'm not going to rehash it here.
 
Well, it's simpler if you just review my linked post, but I'm saying that with the exception of trimming the sleeve (which likely wasn't even necessary) and adding the top bolt, it was a simple bolt-on for me, and the wiring was easy because there's no stator wire like there is on a G3.

I also included a very informative link that details the differences between the G3 and G6 units. If there's a good reason to go with a G3 over a G6, I haven't been able to find it...unless of course you already have a G3 on hand or know where you can get one for next to nothing.

The post I linked you to also has numerous references to the issue of whether or not to uprgade the charging wire, so I'm not going to rehash it here.

I did review and read your link and it was extremely informative! i was just summarizing what i read and just double checking that the 6g altenator really is that easy to install.... im also amazed that it seems more people still opt for the 3g alternator swap over the 6g even with the ease of it being a direct bolt on...well.... as for me, im not running anything electrically over the top where the few extra amps from the 3g is going to make a difference and just for cosmetic purposes id rather Not grind the bracket so its going to be the 6g alternator for me.