3G and 2 wire regulator?????

[Daggar]

Ok... I've been bending jrichker's ear about this setup but I think he's logged for the night. I'll attempt to make this short.

My alternator bit the dust last night. I've been looking into upgrading to 130 amp and have read condradicting instructions for the upgrade. Some suggest that it is DANGEROUS to connect the two black/orange wires to the 3G in the event that the fuse blows on the new power wire. They say that if the fuse on the new power wire blows that the 2 10AWG wires will burn up and potentially cause a fire. Great, I can deal with that logic. The problem is that others say, that if those wires are NOT connected that the charging system will not work because those wires are required to have power for voltage sensing. So which is it? Do they need to be hooked up to the alt or not?

Next: Best I can figure, my car came with not 3, but a 2 wire voltage regulator setup (see the pic).

Now... PA performance has what they call a 120 amp, 2 wire regulated, 2G replacement alternator. It requires no bracket modification and I assume uses all of the stock connections. It does not however, provide many details on the alternator. I have no idea if this 120A 2G replacement has "posts" on the back like the 3G does. If it does.... GREAT! It should make installation that much easier but still does not solve the issue with having (or not having) to hook the stock black/orange wires up to the new alt.

So... Am I correct in assuming that I have the 2 wire regulator setup?
If not, which of the wires do I need to pigtail for the stator wire? (there is no white/black)
Has anyone installed one of these 2G replacements?
Do the black/orange wires get hooked to the new alt or not?
If not... will the charging system still function correctly with just the new power wire run out to the positive side of the start solenoid?

Thanks all.

 

[HISSIN50]

i would think one needs to upgrade the stock wiring if running anything over stock amperage (IIRC, it is like a 10 gauge wire that flows all the juice!). i have thought about beefing up the wiring on my stock alternator even, as it is barely adequate.

Daggar, i dont much else on what you have asked about the wiring connections (as i recall, Joe says to not do it, while others do). i dont pretend to be Joe or Tom with electrical stuff (or much else for that matter) - i might wait for Joe to reply.

i would follow his tip on the power ground upgrade. juice flows from ground to positive - if ground is insufficient, the system cannot be as efficient as possible.

good luck man.

 

[Daggar]

Thanks for the reply Hiss... I've been so caught up in getting the obvious issues ironed out that I haven't had time to think about the things that are lurking beneath. The grounding wire is a good call. I believe that by batt cable and ground are up to the task but I haven't looked at any of the other's yet.

 

[HISSIN50]

Thanks for the reply Hiss... I've been so caught up in getting the obvious issues ironed out that I haven't had time to think about the things that are lurking beneath. The grounding wire is a good call. I believe that by batt cable and ground are up to the task but I haven't looked at any of the other's yet.

yep - the motor ground is the one i would be concerned with. again, the stock motor grounds are not too hot (i need to run an extra one or two myself, just for the sake of doing so).

good luck and bump for ya.

 

[notchman90]

i hooked up the two wires when i did mine along with the 4gauge when i did my 150amp alt. ive had it like that for about 5 months and have not had any problems. I even called up the company where i bought it from and they told me that those two wires needed to be hooked up. hope that helps

 

[Daggar]

i hooked up the two wires when i did mine along with the 4gauge when i did my 150amp alt. ive had it like that for about 5 months and have not had any problems. I even called up the company where i bought it from and they told me that those two wires needed to be hooked up. hope that helps

How did you hook them up? Did you hook them straight to the alternator or did you run some sort of jumper from downstream of the fuse block on the new power wire. Since the information that is being put out conflicts, I guess I have to assume that both are correct.
1. That the black/orange wire DOES need to be hooked up
2. That if the fuse should blow on the 4 guage power wire that the little ole 10 guage wire will be left to roast if there's any significant power draw from the larger alternator.

With those two things in mind (unless I hear different) I think I'm going to run another wire from after the fuse block on the new power wire to the black/orange wires on the car. At least that way, if the fuse does blow then the black/orange wires will also cease to get power. Sound like a solution?

 

[HISSIN50]

With those two things in mind (unless I hear different) I think I'm going to run another wire from after the fuse block on the new power wire to the black/orange wires on the car. At least that way, if the fuse does blow then the black/orange wires will also cease to get power. Sound like a solution?

i had the same thoughts. how about adding a fuse to those wires instead? would that work?

 

[jrichker]

See http://www.autozone.com/images/cds/gif/large/0900823d80167158.gif for a wiring diagram for a 86 Mustang alternator.

Lt green/red wire & yellow/white wire go the alternator regulator plug

The plug you have in hand is the regulator plug. The black/orange wires share one plug to deliver the alternator output to the rest of the electrical system. The missing white/black wire is evidently jumpered inside the alternator. You'll notice that the plug you are holding has an empty place for a 3'rd wire. That's where the white/black wire goes on the later model cars.

For a modded high current 2G alternator use the 2 wire plug for the regulator with no changes. Add a 4 gauge power feed wire with a 125-150 amp fuse between the alternator output and battery. Leave the black/orange wires & connector intact and just tie wrap them up out of the way.

For a standard 3G alternator install, you could either add the missing white/black wire to the regulator plug or get a regulator plug & wires from a wrecked 94-95 Mustang. If you do the wrecked car thing, get the white/black wire & connector at the same time. Then you get to splice, solder & heat shrink them onto your existing wiring harness. The white/black wire on the 94-95 regulator plug goes the white/black wire for the field windings. Add the 4 gauge wire & fuse and you are done with the wiring. Again, you just leave the black/orange wires & connector intact and just tie wrap them up out of the way.

See http://www.autozone.com/images/cds/gif/large/0900823d80167158.gif for all the wiring diagrams for 79-88 Mustangs

 

[Daggar]

Thanks jrichker,

I'm slowly envisioning a plan here. However:

For a standard 3G alternator install, you could either add the missing white/black wire to the regulator plug or get a regulator plug & wires from a wrecked 94-95 Mustang. If you do the wrecked car thing, get the white/black wire & connector at the same time. Then you get to splice, solder & heat shrink them onto your existing wiring harness. The white/black wire on the 94-95 regulator plug goes the white/black wire for the field windings. Add the 4 gauge wire & fuse and you are done with the wiring. Again, you just leave the black/orange wires & connector intact and just tie wrap them up out of the way.

If I were to get one of these plugs from a wrecked 94-95 and splice it into my existing harness... which wire would I splice it into? Since I'm missing that third wire, which of the two available on my existing harness would the stator pigtail be spliced in with?

Edit: And am I correct in saying that the black/orange wires need not be connected at all? I just want to verify that they are not needed for proper operation of the charging system.

 

[notchman90]

hmmmm all this talk makes me think i might have hooked my alt up wrong, im gonna pull those two wires off tom. and see how it works out ill let you guys know. daggar to answer your ques. i hooked the two wires up with the 4 gauge on the same terminal.

 

[jrichker]

Thanks jrichker,

I'm slowly envisioning a plan here. However:



If I were to get one of these plugs from a wrecked 94-95 and splice it into my existing harness... which wire would I splice it into? Since I'm missing that third wire, which of the two available on my existing harness would the stator pigtail be spliced in with?

Edit: And am I correct in saying that the black/orange wires need not be connected at all? I just want to verify that they are not needed for proper operation of the charging system.

Note this is only for an 86 Mustang, no other year.

The 94-95 regulator wire colors are the same as the 86, so match same color wires together. Green/red wire on the 86 body goes to green/red wire on the 94-95 regulator plug, same for the yellow/white wire.

The 94-95 regulator connector will have the white/black wire with it. Splice the white/black wire on the regulator plug to the white/black wire with the field connector on it.

Leave the black/orange wires alone, don't cut or remove or connect anything to them. Just tie wrap them up out of the way.

Here's the link to the 94-95 wiring diagram: http://www.autozone.com/images/cds/gif/large/0900823d801ddb5a.gif

 

[Michael Yount]

Guys - current is DRAWN from the alternator; a larger capacity alternator doesn't PUMP current into the system like a high volume/pressure oil pump would. If your current accessory load requires 40, 50, 60A, then that's what the alternator will supply - whether it's a 65A alternator or a 120A alternator. The big improvement will come at idle when the stock alternator is barely able to put out 30A, and accessories require more.

Daggar - if you're not overloading the twin 10gauge wires now, you're not gonna over load them with the new unit assuming you pop a fusible link on your added 4 gauge. So I wouldn't go crazy figuring out how to bypass the system. If you're worried about it, seems to me the easy thing to do is to simply wire fuses into the 10ga. wires. That way if your 4 gauge fusible link pops, AND you've added a bunch of additional electrics so that you're CAPABLE of overloading the twin 10 gauges, their new fuses will pop alerting you to the problem.

My stock 65A alternator feeding ONLY the twin 10 gauge wires handled my stereo, wipers, a/c-heater blower, twin electric cooling fans, 4-H.O. Hella QI headlights, computer, two fuel pumps (in-tank feeder, and in-line factory pumps), etc. with no problems for 7 years. The challenge was that at low engine rpms, the 65A alternator had a hard time keeping up with the load which taxed the battery. The 95A alternator solved the problem. I did include the large 4 gauge with fusible link hooked directly to the battery. And I also connected the twin 10 gauge wires - just as they were before. Idle charging issue solved - and the system isn't caring anymore peak load than it was before. No car/harness fires yet. 2 1/2 years since the alternator upgrade. The only difference is the voltmeter stays pegged on the charging side even at idle.

 

[Michael Yount]

The reason you needn't worry a lot about overloading the stock twin 10 gauge if the 4 gauge fusible link blows is because 1) they're marginally capable of handling even a 'loaded' stock car's electrical load, and 2) anyone who adds additional electrical accessories - most common big amp items are electric cooling fans and big-amplifier stereos and fog lights - runs new/separately fused power supply to these devices. That means the incremental power load isn't being supplied by the twin 10 gauge wires. You only have to worry about overloading the 10 gauges if you've managed to power all your additional elec. accessories through the stock fuse box. I've run a few 'trigger' (coil side) wires for relays out of the fuse box, but any higher-amp powered accessory (new stereo, elect. fans for example) gets it's own new/separately fused power line directly from the battery or the alternator post. That's the case for the vast majority of tinkerers out there who not only are afraid of/don't understand the fuse box, but simply don't want to run anymore wiring than they have to - and by running from alt/battery they keep the new wiring all under the hood avoiding that thing we all dread - how in the world do we get another stinkin' new wire through the firewall. That's also why almost every accessory I've ever added has instructions which very clearly call for running new, separately fused dedicated power lines. They don't want to overload the stock fuse box/wiring either.

 

[jrichker]

The reason you needn't worry a lot about overloading the stock twin 10 gauge if the 4 gauge fusible link blows is because:

1) they're marginally capable of handling even a 'loaded' stock car's electrical load.

2) anyone who adds additional electrical accessories - most common big amp items are electric cooling fans and big-amplifier stereos and fog lights - runs new/separately fused power supply to these devices. That means the incremental power load isn't being supplied by the twin 10 gauge wires. You only have to worry about overloading the 10 gauges if you've managed to power all your additional elec. accessories through the stock fuse box. I've run a few 'trigger' (coil side) wires for relays out of the fuse box, but any higher-amp powered accessory (new stereo, elect. fans for example) gets it's own new/separately fused power line directly from the battery or the alternator post. That's the case for the vast majority of tinkerers out there who not only are afraid of/don't understand the fuse box, but simply don't want to run anymore wiring than they have to - and by running from alt/battery they keep the new wiring all under the hood avoiding that thing we all dread - how in the world do we get another stinkin' new wire through the firewall. That's also why almost every accessory I've ever added has instructions which very clearly call for running new, separately fused dedicated power lines. They don't want to overload the stock fuse box/wiring either.

My concern has always been about the catastrophic failure mode where the fuse for the 4 gauge wire blows due to an internal short in the alternator. That would leave the current to flow through the two 10 gauge wires, which have a fuse link with unknown time delay characteristics. If for any reason the fuse link has a long time delay before it blows, there could be significant damage to the wiring. Redundant paths are a great backup, but only if the fuse characteristics are closely matched enough so that when the 4 gauge wire fuse blows, the fuse links for the two 10 gauge wires open up before or at the same time, +/- a few milliseconds.

 

[Michael Yount]

I guess I'm wondering how much current the alternator's gonna put out at all if it shorts out internally.

 

[Michael Yount]

Also, no more current can go through the 10 gauge wires than is being drawn through them. With other devices drawing their current directly from the alternator or the battery - I still don't see the potential problem -even in the worst case. Seems to me the worst case is major short from battery to ground - in which case you need a fusible link on the hot side of the battery. Don't know what the Stang system does with that. I added one when I relocated the battery - seems a good standard practice. It's gotta be big enough to manage starting current though.

 

[hllon4whls]

All of that info is great, but here is a simple diagram that I found in 2002. The hosting site is offline now, but I'll host the diagram.

 

[Michael Yount]

Did you leave a link out?

 

[hllon4whls]

No, Michael, just took a minute to get my code right.

I dont have a scanner, so I will scan it in later (at the neighbors). This is just a picture of the printout. I think it is clear enough.

 

[Michael Yount]

Maybe it's on my end - still not seeing anything...