Alright, so I'm working on a project and seemed to have made a grievous error. I am not too well versed in electronics so I'm hoping you all can give me a little advice. I am getting rid of an old Corolla that I had put quite a nice sound system in. I wanted to take the equipment from the car and wire it up so I could use it in my new apartment. I built a box for my speakers and purchased two computer power supplies. The power supply I planned on using for my amplifier/sub woofers is a ROSEWILL| RG630-S12 630W RT. A quick search showed that the yellow wires were carrying 12V, and just as a safety check I used a multimeter to ensure that the resistance across any given yellow wire to another was ~0 Ohms. I also checked the black wires and found that any combination of black wires would still yield ~0 ohms. So, I assumed since there was no resistance they were all connected and I could take whatever yellow and corresponding black wires I so pleased. I clipped the two yellow wires on the 20/24 pin connector and the corresponding black wires as well as all of the yellow and corresponding black wires on the mole connectors and the 6 pin connectors. I put all of the yellow wires together and did the same with the black wires. I powered it up and used my trusty multimeter to make sure I was getting 12V across the two bundles of wires. I was, so I figured I was ready for a test run. I hooked it up and my head unit and... blew the fuse. I looked on some forums (yeah yeah I know by now most of you are shaking your heads at my utter lack of foresight), and noted that most guides said NOT to clip anything off of the 20/24 pin connector. Whoops. I also realized, quite to my dismay, that in my clipping frenzy I had clipped TWO of the ground wires from one of my mole connectors. The extra wire I clipped was the negative for a 5V wire. I have narrowed the missing 5V negative down to only a few candidates based on their position, but I don't know how to find out for sure which on them was originally paired with the 5V line. I thought that there would be some resistance between the 5V negative and any of the 12V negatives if they were on a different board, or rail, or whatever the correct term is, but any given combination of clipped black wires still yields close to 0 Ohms. I also have no idea how to determine which two yellow and black wires were originally on the 20/24 pin connector. I have successfully powered my head unit with the other power supply by clipping only the yellow wire and corresponding black wire from the mole connectors. So, what I need, is for one of you awesome circuitry masters to give me a nifty trick I can use to determine which wires I need to reconnect.