92 Plymouth Acclaim drains battery

Once when it failed to crank I found that some way, some how a battery cable connection was loose. Fixed, recharged battery, drove OK, volt meter chowed charge. Battery dead next attempt, found tiny spark when I reconnected a charged battery again. Question-where is the first place to look for a component damaged by running with a loose battery cable? Curious-does this car, a 4 cylinder, have an external regulator?