I have a 1998 Nissan Maxima. Yesterday when I went to leave work it wouldn't start. The engine would just make one click when I tried to turn the key. The battery is working fine. I also replaced the starter in February of this year, so shouldn't be starter. I had someone hook up with jumper cables for 30 minutes just in case and it still just clicked when i tried to start it. It won't even try to turn over. The lights and air all work fine, so I know the battery is fine. This happened a few months ago, and a Nissan mechanic who just happened to see me broke down told me it was the anti theft security system. He it turns on something that keeps the engine from starting if it gets tripped. I didn't get his information so I have no way of contacting this mechanic. I guess I don't remember what he did to reset it. I thought he unplugged the battery for 15 minutes, put the car in neutral and it started right up. When I tried it it didn't work, and i have tried several times in neutral and park. I have tried removing the fuse for antitheft system and unplugging the battery for 15 minutes and plugging back in, this also did nothing. I have tried turning the key in the driver side door slowly back and forth, as well as the passenger door. This also did nothing. I am out of things to try.