this evening i was changing one of my o2 sensors on my cat. when i finished up the job, i went to un-hook the negative power on my battery, even though i disabled my alarm, i completely forgot that it was going to go off when i cut the power on the battery, anyway the alarm went off for a minute or so, then i plugged back in the negative, and disabled the alarm. as i was driving home no more than 30 mins later, my check engine light comes on, and my interior/exterior lights dim a tad, and my speedometer completely drops to the pin. so driving home the rest of the way with no speedometer, my lights start to fade badly, and my tac starts to drop as well. when i applied pressure on the gas, it would start to stutter, then finnaly my car shuts off, and all my lights are barely visable. so i stop wait for my buddy to come by, and we charge the battery via jumper cables, and then i was able to make it the rest of the way home, barely. currently my battery is being charged in teh garage.

my question is, what could have caused this? the battery is obviously fine if im able to charge it, and get the car to start. so i was thinking alternator, but i didnt know the alternator would cause the speedometer to drop and so forth.

any input would be greatly appreciated, and i have work and school. and i need to solve the problem as soon as possible.

thank you

 

chck your fuses