I had to have my 2002 Mustang
GT towed to a repair shop, this past Saturday morning, because it wouldn't start. It cranks over (VERY strongly, LOL, thanks to the Optima Yellowtop battery I bought for it, the night before!), but it won't start. The shop I had it towed to diagnosed the problem today as the fuel pump isn't operating, because it's not getting any power through the battery junction box (or, power distribution box, or whatever it's called) - this is the box with the fuses/mega fuses/relays, that's mounted right next to the battery. I suspected this might be the issue, and I'll explain why.
I drove my wife to her job on Saturday morning, and I had no problem with the car. When I got back home, I was trying to get that nut off of the stud on the battery junction box that the cable from the alternator connects to. The reason I was doing that is because when I bought the car almost four years ago, I had to right away replace both the battery and the alternator, because the car wouldn't start the day I brought it home. I bought a Motorcraft battery, and an higher-output alternator, rated at 250 amps, I believe (it was actually less money than some of the rebuilt, standard-output alternators that were available for my car, and the dealer I bought the car from compensated me partially for the parts costs). Due to the higher output, it was recommended to install a thicker-gauge wire, so I bought an upgraded wire from American Muscle. However, I've NEVER, in almost four years of occasionally trying, been able to loosen that nut; I've only succeeded in distorting the box, because I'm assuming the copper plate inside was bending (mine looks like the one in the picture I've attached to this post). The nut seems to be "welded" to that stud; I'm assuming this is due to a combination of electrical current flowing through it; age, and underhood heat. When I was trying to loosen it this past weekend (yes, I've always sprayed penetrating oil on it, before trying to loosen it), the whole stud felt almost "loose", as if it was broken (or, nearly broken) off of that copper plate.
As a stopgap measure, I simply attached that upgraded alternator wire directly to the positive terminal on the battery (leaving the stock alternator cable in place, obviously, because I can't remove that nut), but I'm not sure that I'm getting the full benefit of the higher-output alternator I have, and I'm not sure it's necessarily good for my battery. As I spent $231 on that Optima battery, that's now become an important consideration for me, again - that's why I was messing around with it again, on Saturday. Besides it not starting (it actually started after I was messing with that nut/stud, but was supporting, as if it was running out of fuel, which it was), I have had other issues because of it, including the car overheating once, due to the electric cooling fan not running (the fan wasn't bad; when I squeezed the two halves of the battery junction box together with my hands, it started running).
So, anyway, if I understand correctly, that battery junction box only came as part of the whole underhood wire harness. The part number for that harness for my car, as given to me by a Ford dealer today, was 2R3Z-14290-AA (that number only fits certain 2001 & 2002 GTs, depending on build date, and there's two different harnesses, depending on if you have a Mach 460 or a Mach 1000 stereo system) and, of course, it's long since obsolete. I found a couple of harnesses on eBay, and I'm waiting for responses from the sellers as to whether or not they can provide me with the Ford part number, or the exact kind of Mustang it came out of.
Here are my questions, if anyone can answer them:
1. Is that battery junction box the same across all the different wire harnesses? Can I just go to a junkyard and get one off of a Mustang that's a 2002 (or, thereabout), and simply remove the wires from it, and then substitute it for my damaged one, and simply plug my existing wire harness into it (taking care, of course, to make sure each individual wire is plugged into the appropriate slot)?
2. How does that box come apart? I took mine off of the bracket it's mounted to, and was able to tip it forward (towards the engine), so that I could see (sort of) the underside of it, and the black plastic cover on the bottom of it the whole, thick wire harness goes through and up into the box was loose, but it looked like there was a red plastic piece that the wires ran up into, and I couldn't figure out how to dislodge/remove it. I couldn't really position it into an optimal position for what I was trying to do, as I could only stretch the harness so far, and didn't want to inadvertantly pull any wires out of it. Anyone have any pictures on how to take it apart?
3. Anyone have the correct harness, or the battery junction box, if that part is the same regardless of the harness part number, that I could buy, or know someone who might have it?
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