Just installed a new alternator, battery, serpentine belt. I can turn the key on, everything lights up (dash, radio, fuel pump, etc) when I turn to start, its like it shorts, and everything goes dead. all I hear is one click and then complete death. I can disconnect battery, reconnect and do it all over again. any suggestions? its a 96 metro with a 1.0. thanks

I would suggest cleaning out the battery terminals thoroughly with a wirebrush. Soemtimes they make contact but not good enough to support the current draw required to start. If the voltage spikes or changes in certain ways, it can upset the engine computer and cause it to hang up.