I've got a 2001 Nissan Sentra driving me crazy. The problem is that when I turn the key to the "start" position, I hear a click and all the electrical dies. When I jump it, the car starts fine.
This is where it gets strange. I can come back to my car and the electrical works fine. I can play the radio, honk the horn, crank the A/C with no problem. As soon as I turn the switch to the start position to start the engine everything dies again. I tried cleaning the terminals and once again I had power... until I tried to start it. Again, "click" and my electrical stops working.
I had the battery and alternator checked - both were fine. Even after all of the electrical dies on me, the battery itself still has a charge. Removing the lead from the terminal and reattaching it makes everything work again until I try to start it.