Mitsubishi Repair: mitsubishi eclipse: headlights/horn/other stuff staying on and some inop, little black boxes, obdii scan tool

Question
i have a 1998 mitsubishi eclipse turbo...the other day i installed a universal o2 sensor into the manifold by splicing the wires from old one to new one.  i then went to clear the code with my obdII scan tool and it would not power up from the cars aldl port.  i decided to unhook the positive cable from the battery to clear it all.  i then put the cable back on along with the 4 white wires on the post going to the fuse block underhood.  when i backed the car out i heard the horn honk and shut the car off figuring something shorted with the horn, i then noticed that the headlight would not shut off only the marker lights with the car shut off.  i also have no radio,blower motor fan,interior lights and who knows what else..  however i do have dash lights, brake lights, ac light comes on and car starts up.  the only way to kill the lgihts it to unhook those 4 wires going to the fuse block..  im lost on this one and not sure what happened to the car from just unhooking the battery?  any ideas would be great on this one, thanks

Answer
Ryan:Have you checked the fuses to see what they are telling you? What of the relays and larger fuses under the hood in with the engine in those little black boxes? I tell you, you have to have one hell of a large short. I don't think I would have spliced wires using the old ones from the old 02 sensor onto the new 02 sensor. Either the computer does not like that at all. Or else somehow you have wires touching that should not be touching. They are pulling away the power, you need to get a voltmeter, repair manual(need this for right readings) start with the battery and find that short. But I bet you have killed off some large relays too. When I clear the computer, I take off the neg cable off; wait for a bit and then put it back on. I don't know about taking off the positive cable. Still you got a large short someplace, so check those fuses, large and small as well as the relays. Then use that voltmeter to find your problem. Hope this helps and good luck! Linda