Well after completing the big 3 upgrade (2AWG power, 2AWG ground) on my 08 Mustang GT, I managed to almost turn my car into a raging inferno. Long story short I'm assuming when I reinstalled my alternator, I somehow bent the ring terminal to my 2 AWG wire which rubbed against the alternator casing causing a short and leading to my 200 amp fuse blowing but not before setting the factory 6 AWG wire almost on fire. The car turned off I believe right after the fuse blew.

So I now need to replace that 6 gauge wire and change my fuse but I was wondering if I can leave out the 6 gauge wire and only run the aftermarket fused 2 gauge wire to my battery or would it be best to have both wires connected.

My next question would be, could I possibly have damaged anything else with my screwup. I already had the alternator tested and it was fine.

 

Woof!


IMO, single, bigger the better, as it will travel through the path of least resistance, so should be good with just the 2 gauge.

That I can´t speak to since your still not 100% certain yourself. Though, so long as what you state, and assume to be the case, it´s doubtful anything further was FUBAR´ed. Though I might check the battery itself and grounding wires. Shorting it at the point you mention would just cause a giant drain. Certainly f´ing up the wires potentially and possibly causing an internal short to the battery itself, but everything else should be good.

 

i would not use it just zip tie it away.

 

Sounds good since Ford doesn't sell that alternator to battery wire individually, it comes together with the rest of the power wires and I think it's like a couple hundred bucks.

Ok so I'll have my battery tested tomorrow but how do I check to see if my grounds are good?

 

you do not need the factory wire. trace it back to the battery and remove it if you choose, just be sure to keep the ring terminal using the alt. side inside the little "cup" of the alt. so you dont spark or cause a fire. Also, be sure to fuse that wire at the alt. You shoudnt have damaged anything, but i would look very indepth at your motor, and all wires near,and touching the alt. power wire to be sure there are no burns on any of them as much as you can.

 

and to see if your grounds are good, use a dmm set it to ohms, and put one wire on each side of the ground wire and check resistance, should be no more than the resistance of the wire itself. if its more than that, find a better spot.

 

Check the main ground, as this is the one you say shorted, correct? Or was it on the alternator itself, if that´s the case check the alternator´s grounding line. Which I assume since this was a ¨Big 3¨ upgrade, you replaced that as well. As the above guy stated, just a quick check wtih a multi-meter. Likely that no connection damage was done, but the insulation might have gotten roasted with this.

If you´re going to not use the 6-gauge, remove it as stated, do not just zip-tie it off.

And to verify the ground(s) use the multimeter, but use another ground point on the chassis for 1 of the multi-meter´s leads to make certain your getting a good ground to the body. Resistance, even a little on the main chassis ground is not a good thing. If you replaced this line, or added to it scrape the crap outta that contact point to make sure there´s no paint, oil, or anything else there that can add resistance.

 

I'm still a little stumped on how the ring terminal I added touched the casing being that the terminal was bolted on tight and insulated but it was, good thing my 2 gauge was fused. I'll double check all my other wiring for burns as well.

Thanks....

 

It was the ring terminal on my 2 gauge power wire that touched/shorted on the alternator casing which then blew my fuse almost setting the 6 gauge wire on fire. I'm going to remove the 6 gauge as recommended but now I'm a lil nervous on this happening again because I thought I had it secure the first time I installed it but I must of somehow bent it down on the alternator case when I put the alternator back on.

As far as the ground is concerned, the ground from chassis to battery negative I connected it to a bolt on the strut tower which I sanded down to bare metal. The ground from engine to battery negative was connected to the alternator mounting bracket.

I'll test my grounds for resistance tomorrow on these wires and I'll update my findings. Do I need to remove the factory grounds as well since I'm getting rid of the alternator power wire? And there also 2 other factory power wires, 1 going to the fuse box and the other looks like it's to the starter. These are ok to leave intact, correct?

Thanks a million for your time and help bud

 

Need to? Nope. Most leave ´em. Won´t hinder anything as stated, path of least resistance is used.

No benefit really to replacing them, so, yes.

Not a problem.