My 99 V6 cougar wont start! I notice when driving the car the head lamps and dashboard lights would dim while driving it. Now for over a week it start that when i put the key in all the dash lights would work but when i turn the key the engine does nothing! i played with the controls and determined that when i turn the headlamps on a humming noise would come from the engine and it would start. Then it started happen more often. I brought it to a mechanic and mention the alternator he diagnosed it and said the laternator it fine and he said some wired were carowded and fixed them. i then work but that evening it did the same thing... then the next day it worked! now 3 days later doing the same thing just wont start.... PLEASE help!