i have a 96 gtx and i just ot a new battery and starter, the starter cranks the engine for about 20 seconds and then after that it doesn't turn the engine over at all. at first it seemed like the battery was dead and just didn't have enough power. the battery still has a full charge afterwards and the power wire gets very hot. it was running fine a week ago. any ideas why it is struggling so much to turn the engine over?