I forget which wires you used, but I remember drawing you a nice picture of your car exploding if you didn't upgrade the wires to thicker... I'd say that was specific. Yes upgrade the wires. Also do you have any other subs, big amps, microwave oven (hey you never know, it's Manheriano! ) plugged in?
As for the disk boot error, I would say that your HD is not fully spun up and functional before the mobo says, "what the hell is plugged into me" and starts looking. Since the HD is not fully awake yet, it's all sleepy like, and misses the mobo's call. Then when it is awake, the mobo has already moved on to try other devices during POST. Now, unless one of those other devices has an OS, then it can't do anything because to the computer, there is no HD. Look in your bios. There might be an option for IDE delay or something similar. Set it to the maximum like 3 or 5 seconds, and that way the mobo will refrain from looking until that time has passed hopefully giving your HD the time required to take its coffee and get it's lazy *** working. This is strange though because you have a 2.5" drive, and only the crap bottom of the line ones can't stand -11C. Usually lower than that. I would be wary of the drive.
Of course it could be other things but I advise you to check that first.