Ford Repair: 97 Ford Contour, ford contour, loose ground

Question
When I turn on my headlights all my lights flicker inside and out. Only when the car is running plus the check engine light stays on all the time even with the headlights off. I just replaced the alternator due to this problem and the check engine light went out for a couple of days and it slowed down the flickering. But two days later it was back doing the same thing. What is the problem? I live in a small town and not one person knows the answer. I'm really counting on you advice. Thank You

Answer
Have you're local parts store check the engine codes.Most provide this service for free.It will tell you why the check engine light is flickering.Or you could tell me the code that is stored.As far as the lights go,have the battery tested while you are there.Sometimes a loose ground wire will cause this to happen.The engine codes are needed to properly diagnose you're problem.One possibility to think of is the headlight switch.