Magical Electricity Question (alternator/distribution block)
 

So, I am upgrading to a 160 amp FD alternator, and I am trying to figure out my cluster fuck of a wiring nightmare I have going on under the hood. I currently have the stock white wire to the main fuse running from the alternator, as well as the two wires for my upgraded headlights, one for right and one for left. Apparently all of this draw through a messy stack of poorly soldered connectors on small wires has caused the terminal on the stock alternator to heat to the point of glowing orange. So pretty much all of the wiring attached is burned and hard as a rock up to 2" or 3" up the wire. I have a question about my new proposed setup, and if there is any fundamental issues with it that I am just not seeing.

I want to run a large 2 or 4 gauge wire from the alternator, to a decently beefy 4 way distribution block usually meant for audio applications. From there I branch off the stock white wire to the main fuse, and then the head lights. Does anyone see any issues with this, or have any suggested improvements? I'm just tired of having a rats nest of wires running to a single alternator stud. I'd like to be able to run the one large cable to the firewall or wheel well and then hide the wires a bit better, and hopefully improve the overheating situation.

I see no reason why this solution would not work, but I also see no reason why this would fix your thermal problem.

Just be sure to fuse your headlight wires at the distribution block.

Holy hell, how much current are your headlights pulling? Added to the main wire, I see no reason why this setup should generate so much heat. Even if you added a 0/0 gauge wire to the alternator -> distribution block link, it shouldn't change how hot the thing runs, I feel like the more likely scenario is that you've got an intermittent or weak short between the hot pole on the alternator and the ground of the car - this ground on the car could potentially be the case of the alternator.

I can't see any issues with adding a distribution block between the alternator and the fuse block (apart from creating an additional potential failure point) provided that you do a better job of terminating the endpoints of the wire than was the case in your present setup.

2-4 ga wire, incidentally, is unnecessary for such a run. As fooger pointed out, it wasn't the thickness of the wire that caused your problem here, but the quality of the end connections. Obviously you are somewhat limited in a terminal-block application by the wire gauge which the block is designed to accept (4 AWG seems to be common) however I would feel perfectly comfortable running 10-12 AWG wire for this application if it were my own car.

On the fusing issue, you might consider using a distribution block which is internally fused, such as this one: P3 Gold Fuse Block 3x4 AWG In 4x8 AWG Out 263-689

160 amp FD alternator?

Well, I think mainly this will help me because of how poorly I have soldered and crimped the connectors on the current wires, since they are tucked down beside the engine with such little space to work. This will allow me to move this connection point up and out of that little crack, and allow me to pull the white wire to the fuse block out of the harness it's trapped in and crimp a proper connector onto it. I'm sure most of my heat issues are from gaps that the current is jumping. The lug terminal I soldered on to the white main wire is too big, and there is a pretty large void or voids inside of it where the solder didn't fill. So that electricity is arcing inside of the terminal. Then you have the gaps between each of the 3 lugs that I have sandwiched on the alternator output stud. I just like the idea of running one good quality cable with a properly crimped connector off of the alternator, and do the branching off of the other wires from a block, instead of all off the same stud.

Yes, 160 amp. Upgraded, remaned Mistubishi alternator off ebay. We shall see how that goes. The seller deals in alternators and starters, and have a nearly perfect rating.

Which ground are you referring to Fooger? I've looked at all of the grounds I could locate visually. But I'm sure we have several that I couldn't find.

I'm not referring to a standard ground connection; instead, I am referring to the possibility of a short somewhere between the "hot" pole (+) of the alternator (the place where you connect your big, thick 4 or 8 gauge wire) may be shorting to the case of the alternator, which is the base of the primary ground of your entire engine electrical system via the "squeeze-fit" connection to the block at the "long bolt" on the alternator.

Unless I'm mistaken, when functioning properly, the case of your alternator is ground (-) and the pole of the alternator is hot (+). If this is the case, then shorting the case to the pole is a really bad thing, as it would be an unfused power short in your car, which could cause some pretty extreme heat. If the shielding on one of your headlight wires degraded and made contact with a ground, either at the block or against the case of the alternator, it could be the CAUSE of the damage and heat instead of the EFFECT as you propose. I should note, however, that I'm not familiar with how likely the alternator is to "self-destruct" under such a condition - basically damaging the alternator beyond function because of the short. Another possible reason for the short could be dirt on the contacts; however, building sufficient electrolytic material between the pole and the case under normal operation is highly unlikely over the expected life of the alternator.

You are unmistaken.



A direct short between the alternator's output and ground would result in the almost instantaneous destruction of the rectifier stack which sits between the windings and the output.



Also, for what it's worth, 160 amps is more power than the alternators commonly used on large tractor-trailer trucks produce. I would take this rating with a grain of salt.

160amp is ridiculously high for your needs. I'm slightly confused as to what a passenger car could use 160amps for, short of a massive 50billion watt audio system. If it really is a 160amp alt, and he rewound it how I think, you are going to see a lack of amps on the low rpm range compared to a FD stock alt. I'll be interested to hear back on your low rpm amps/voltage - remember, we are already underdriving the FD alt.

FWIW, I picked up a new (not remanned) 100 or 120amp stock FD alt with a lifetime warranty from the 'zone or o'reillys locally - for less than you paid.

Oh well. More is better yo! I will admit electrical related things are my weakest point. I would not make a good electrical engineer.

So, correct me if I'm wrong on this. The connector on the alternator is not a signal wire or anything for the internal regulator, but simply wiring for the indicator light on the dash? Since it's internally regulated, it needs no other wiring for that aspect, correct?

So you really think I'll have an issue with this alt? I wouldn't be heart broken returning it, or reselling it and picking up a stock replacement FD alt at ~100amps. Had I simply done the math first, I would have seen that 160 is indeed way overkill. My headlights draw 260 combined watts, stereo at about 300, and fog lights at about 200 watts. Add the draw from everything factory, and surely I'm not exceeding 80 amps total, for everything.

headlights + stereo + fog lights = 54 amps at 14v

you have 460 watts of lighting? that seems awfully high...

It is. My setup is "not street legal", but here in Alabamer, it doesn't matter. No inspections and cops no give a shit. It's not like my setup blinds people like poorly done HID conversions.

But again. Would this alternator really give me issues? I'm not seeing how a higher potential amperage output is going to somehow not be good.

It'll probably work fine. I merely question the validity of the 160a rating. But, of course, the stock alternator wasn't your problem in the first place.

Don't be a chicken, just run the thing.

Yeah, I'm quite sure the stock alternator wasn't the real issue. But because of all of the heat the positive terminal has been put through, I'd rather have a new alternator. Plus at the amperage requirements I have, the stock 60 or 65 amp output probably wasn't enough. Plus I would imagine that rating has gone down quite a bit in the 18 years of the alternators life. The plastic shield around the stud is melted and the stud itself looks pretty nasty from the extreme heat. I'll do a good checking of everything I can find to check and see if anything looks to be shorting, or if a ground is bad.

The Fiat 500 comes with a 140A alternator.

The miata has the worst alternator ever. It can't even keep the voltage up with the headlights running or the a/c running. Let alone you have both on.

If I have everything on, you can tell it. Lights dim a lot, and the idle barely holds. Which that is more of an IAC or similar issue, not so much the alternator. That is one of my hopes with the higher output alternator, is that my lights will be more steady with accessories running. I have a feeling my stock alternators voltage output was lower than it should have been, and being close to its amperage limit didn't help matters I'm sure. I have a feeling most of my heat issue was the poor crimping and soldering work I did on the wires at the alternator stud. Using a big lug for small wire and trying to fill the space with solder full of air pockets, from what I understand, is not at all good. Electricity arcs across the gaps, causing heat. Which is why the lug and the stud would be glowing bright enough red/orange/white to light up that side of the engine bay at night. Then again, I may be talking out of my ass. Seems correct and I'm sure I've heard that somewhere before.

My voltages drops below 11v when I have my lights and a/c running at idle. I've seen it go as low as 10.5v...at that point the LC-1 turns off. One of these days I'm going to convert to an FC alternator (i have 1.6L). I should have done it when I put on the current alt, but I needed a replacement asap, and the local store didnt have the FC alternator, I'd have to drive about 20 miles to get it and the voltage regaulator in mine was going out and I had to monitor my voltages and turn off the ignition while driving when I saw the voltage spike...

Fixed that for you. The NB alt is bauce.

:cry: