well i got a 02 neon with an auto trans and it was running fine then the next morning i went to start it and nothing. had the starter checked and it was fine. new batt and terminals on bot pos and neg and still nothing. there is A code in the gauge cluster p-1684 which is the batt disconect i know but how do you get rid of it or what can i look for or?

 

Pull the fuel pump relay in the engine bay for a few minutes. It will clear codes without having to disconnect that battery. That, or after the car is started like 50 times again, the code will self clear. It's a dumb code. No CEL from it, just pick what you want to do.

 

I had the same thing happen to mine. it ended up being one of the relays. can't remember which though.

 

Happened to me, but it wouldn't even attempt to crank over. Turned out to be the sentry key system (the anti-theft device that won't allow the car to be started using a key with out a programed chip). It malfunctioned and they replaced it under the 80,000 mile warranty.