I have a 94 Honda civic ex 5 speed with a y8 swap z6 head and z6 wiring harness. I replaced the alt. about a week ago and charged the battery cause the old alt. drained it. It ran fine for a good 5-6 days. Now the battery light came back on. The battery is good just not holding its charge. If I leave it off for 5+ hours the battery will die and wont start. When driving it, it runs fine and wont shut off. I know its not the alt. and battery. What else could it be?