Fixing the Subwoofers

FINALLY! After four months I've discovered what was making my subs work so strangely! This is definitely worth noting as it is likely a very common problem and could stop you needing to replace your subs/amp if you have the same symptoms.

FAULT FINDING:
I took the system out of the boot while fitting the coilovers and when I put them back in they were almost inaudible. Everything appeared to be working so I fiddled with the settings on the head-unit for a few days, but they were so quiet I didn't even notice the fuse had blown at some point. I replaced it, but they kept on blowing after a few days so I checked all the wiring for splits where the metal could be touching the car somewhere. They were all fine.I thought itcould be an earth problem, but if the black cable isn't grounded properly then the amp wouldn't turn on at all. I then checked and re-checked the remote cable from the head-unit to the amp, as this was a horrible problem I had with the system in my Escort, but it all just looked hunky dory. The speakers were moving too, wildly back and forth from one extreme to another, so they were definitely getting a signal.

As for the sound, most of my passengers were convinced I was losing my mind, as the Infinity Kappa's in the doors are pretty bass heavy as is, and kept telling me nothing was wrong. After a couple of busy months though, lugging round a small person's weight of subs and replacing fuses every 5 minutes, I just had to get to the bottom of the quiet running or get rid of the install altogether.

I'd checked and re-checked everything, so the problem had to be inside the components themselves. If a circuit had gone somewhere in the amp then I'd have to buy a new one, but luckily [i guess] the problem was inside the sub box. I guess it must have been stored somewhere damp before I bought it, plus the Scoob's boot and my porch probably weren't much better, because the wiring on the back of the speaker-terminals had started to really corrode in some way. I don't know if you can quite see in the photo, but it's a white powdery crud that covered the brass terminals and was starting to move up the copper cable inside the plastic sheath. I only know of aluminium corroding in this way, never copper, brass or gold-plated bits, so I suppose it might have been some alloy in the solder[?] It was the joins that held the worst of it and when I was checking one wire the crumbly solder broke straight off. Idon't know how the difference between these corroded wires working and breaking was sosudden, because it looks like they've been rotting for a while, but at least it's an easy fix and peace of mind at last!

FIX:

I cut the cables off a good cm past the end of the corrosion, stripped the ends and, instead of soldering them back on, I crimped on some new gold-plated spade-sockets, £3.99 at Halfords, but at least I know this won't happen again. I then took the brass spade-connectors off the terminal, burned the solder off them on the cooker and gave them a good rub with emery, before wiping any trace of the corrosion off everything. I hooked up the new spades and wrapped them in a nice piece of heat-shrink. As soon as I turned the head-unit on the bass was back! YES!