So you want to do the 3G alternator upgrade README

[IPreferDIY]

One possibility that comes to mind is that maybe your 3G is only a 95A one. I have no idea how to tell the difference, but I suppose someone had to raise this possibility. Edit: I just had a look at Google images and I guess it would be obvious, but ...

The only other possibility that comes to mind is that there's something wonky in your electrical system. I would have no idea where to go from here.

What size fuse do you have on your sub amp?

[sly]

[DerekTheGreat]

The amp has a 175 amp fuse on it IIRC. Amp itself is a JBL GTO-5EZ, it's not a ground pounder by any means lol! Never thought I'd have any problems with any of it but this is me! Based on sly's pic I've got a 130 amper. Maybe the ground for the amp sucks, it is just a 1/4 screw and those star type washers going into an area just to the right of the amp. I didn't do the install, CarTunes did. If I should make another thread for this I will, I don't mean to pollute the 3G thread with this stuff, just figured I'd post it all in here since that's why I originally did the swap.

[HiFiMerc]

I've done the 3g upgrade in my '90 and my dads '91. The one in my dads car cares not if everything is running. No dimming, ever. The on in my '90, will still see occasional slight dimming under heavy loads. Not sure why. The 130 amp one in my '92 will dim slightly when the stereo is about maxed. Meh.

[IPreferDIY]

It looks like the JBL GTO-5EZ puts out a maximum total of 1075W and has three 30A fuses. I doubt you'd be maxing out all of the fuses with bass hits in multi-channel use, but I really don't know. Your headlights would presumably be no more than 20A. I'm not sure how much current everything else would be drawing. Do you get the dimming at highway speeds? AFAIK, the 130A rating is for a certain RPM, so pounding your bass at a red light might be a bit much for it.

[sly]

ok yeah... your amp is just a little more then mine and I didn't nead any capacitor for it and I only get mild dimming (re: barely noticeable) with full load AND pounding. (AC, lights, night time, etc)

I also have headlight relay mods on all my cars too... so that's something. The dash dims in the 88 a bit, but it also does that with the blinkers... so I chalk that up to the weak wiring in the dash. The 93 gives zero cares and works great. But then they were optioned with 130A alternators for the fleet packs and had the basic wiring for it already. Just a headlight relay mod on that one.

If the charge cable on your alternator is at least 4 gauge, then you should have no issues. And as long as your amp power wire is 4 gauge (power and ground cables), you should be fine. A good ring terminal on that 1/4 bolt should work fine. If it's a sheet metal screw, you may need to replace it with a bolt and nut to make sure it stays good and tight with all the good vibrations.

Though, considering that your amp has a peak current draw of 100A, you may need a bigger alternator for the real good head shaker tunes.

[DerekTheGreat]

The car used to dim all the time, even at highway speeds, so bad you could see the lights dim down and the dash lights dim. With the capacitor (I did that install myself, woo!) installed any time the thing is above idle I don't seem to have much a problem at all, very slight wincing at the heaviest stuff, and by heavy I mean like Enter Sandman by Metallica or something, I'm not a hip-skippity-hop guy at all. Capacitor made a big difference at speed for sure. At idle, it sort of works. For quick bass hits from a kick drum or something it doesn't wince much at all but the buzzy buzz of a bass guitar or something seems to wipe Mr. Capacitor out and once he's out the dimming happens until the song gets off the bass.

Headlight relay mod... VCV mentioned something about it and said something about a kit that might be plug and play for boxes, any truth to this? Is there a sticky I could search for? I guess my big concern is just the ECM, I don't want to fudge it up and I'm a little worried that I might. If you guys say there's no issue then cool, load off my shoulders. I once had a Grand Am with a four channel amp (that's now in the Fury) and I was jamming out to some AC/DC (Can I sit next to you, girl?) when the stereo just dropped out and the ABS light popped on. ABS module took a dump and in that car they're somehow tied into the stereo... Replaced that and didn't have a problem but you can see where my worries are stemming from...

Charge cable is indeed 4 gauge, well came from a 3G equipped early/mid 90's Continental. Goes straight from alt to battery with no other modifications and wire is free of corrosion, all terminals were cleaned up and stuff. I.. I... I'm still using the original charge wires, or should I say they're still connected to the alternator along with the 4 gauge wire. I used one ring terminal to connect both to it along with the 4g cable. Guess that could be causing it, I didn't see the issue but I couldn't figure out parallel resistances until the other day either. I think you're on to something with that ground, it is just a sheet metal screw and when I was back there I didn't get it tight for fear of stripping it out. That's all on car tunes though, although I might just fix it myself as I'm never satisfied when other people work on my garbage.

[IPreferDIY]

Using two charge wires instead of one shouldn't be a problem if they start at the same point and end at the same point without any funny stuff in between. That's basically the same as using one bigger wire. Definitely fix the body ground. I'd never use a stupid sheet metal screw for a ground point. If there's an existing bolt nearby that you can use, great. Otherwise, use a bolt and nut (and washers if needed). You might want to sand down any paint for a better metal-to-metal connection.

[ssme]

Has anybody found a fix for the constant belt squeal associated with the upgrade. The mass of the rotor to turn is greater due to the larger size and the belt deflection is minimal so at higher rpms you start burning your belt. Once i built my 4r70w aod this has become a problem. these alternators on serpentine drive belt cars dont have this problem as the belt wraps more of the pulley. if you change to serpentine belt config then something has to be done with a/c setup.Does anyone have a belt adjustment to put more belt on the pulley to prevent the burning squeal?

[BlackVic_P71]

Never had belt issues with my original engine, or the Mustang belt setup I have now.

[sly]

I have a small squeak on initial startup, but it's from my power steering pump's resistance, not my alternator.

[Kodachrome Wolf]

I would possibly try a different belt. When I put the 3G on a '87, I had to put on a K060515 belt, or one that was about 51.5" long since I couldn't get the regular one on. The replacement fit well and once properly tensioned, doesn't make any noise.

Your alternator isn't binding or making any bearing noise, is it? I could imagine one that is not turning freely could easily eat a belt.

[87gtVIC]

No squeals here with the upgrade.

[HiFiMerc]

Mine squeeks a just a bit at start up. I am running a smaller pulley on it though, that might be why.

[ssme]

HiFiMerc / Sly, I had the same issue on startup with mine also and could live with that. Once the rotor speed catches up with the belt it stops. I went a lot smaller on the belt and never could lose that first little squeal on startup. My transmission 2/3 accumulator shattered and burned up forward clutches trying to get car home so I rebuilt it. Seeing I installed a 5.0 H.O. last motor i decided to put 4r70w internals in trans. Its a lot better performance and throttle response but the alt belt stays squealing with the higher rpms. I rather not swap alternators back so if there is no easy mod or bracket to refit i will just change the planetary etc back to AOD.

Black_vic p71 ,Is mustang serpentine like MK7 if so what did you do to keep a/c working without a lot of fuss????

Thanks