First I cleaned alot for white power from my battery posts. Then I disconnected the positive cable from my battery so i could change the ignition coil. After changed, I double checked the coil to make sure it was connected properly. Then I reconnected the positive cable to the battery. When I tried to start the van, it would bearly turn over. My lights are very dim like my battery is going dead. It was fine before that except it wouldn't stay started. I had my starter and battery checked and they are fine. What could be the problem? Thank You in advance