I have a '90 classic. Last weekend I went to start it and all it would do is make a single clicking noise at the starter relay and the lights would get dim while hitting the starter button. I did a load test on the battery, and found I had a week battery. (so I thought) It ran good all week until today, it started to do it again. What would cause this problem, and why did it go away for a week and now its back. Any ideas would be greatly appreciated. thanks!