Chevrolet Repair: electrical?, chevy cavalier, fuse block

Question
I have a 1988 chevy cavalier when it is damp out the car stalled and started right up.Just last night I had a rude awakening,I was driving and the car just stopped,no warning nothing.It wouldn't start.So after I had it towed to my house the next day she started right up again,as I was getting ready to go to work(at night) it started right up,until I turned on the headlights,they dimmed a little then the car stopped and I could not start it again.The next day she started right up again.I have a new battery and an alternator.I am stumped.Please help.thanks!I have a new EGr valve,a new fuel filter and a new igniton regulator

Answer
From here it sounds like a loose or corroded connection(s), from the batt. to the main fuse block. Check all connections from batt. to ignition switch, AND all ground leads. Also check voltage at batt. when idling with nothing on, with volt meter, it should read between 13.4 to 14.2 volts when completely warmed up. Did any of the "check engine" lghts come on or a "low voltage" light come on?