Here's my "check charging system" warning story: Bought the 2005 Explorer Sept. 2014. Bad battery, so bought a new one. A few months later, bought a new alternator. For for the last year, the warning light and beep come on, no pattern except that it started out only occasionally, gradually sounded more and more often, but with no pattern. On and off once, twice, then good for a few minutes, then again. Gradually, it got to 35 times or more just going a half mile. So I take it to a repair shop, they run it, hook it to diagnotics, they can't get the warning to come on. I pick up the car (no $$ charge), it runs without a beep for about 3 months, then the beep on and off starts again, gradually sounding more often. This time I take it to a Ford dealer.service place, they drive it some, hook it up to diagnostics, and it never sounded for them, either. They charge me $100 for hooking up to diagnostics. I get the Explorer again, and it drives without a beep for about a month or so, then starts beeping again, gradually sounding more often. I wait until it sounds off and on 100s of times an hour, just sporadically, no particular pattern. I take it to the first auto repair place, they drive it a while, hook it up to diagnostics, find nothing. I get the Explorer back this evening, and it didn't make a beep all the way home. I could live with the warning light, no big deal. But the beep lasts 1 full second, and it is LOUD! It's a conversation stopper. You can hear it over the radio no matter how loud the radio is. Nobody will ride in my car anymore because they can't stand it. I cannot believe nobody on this planet knows what the problem is. Ford has invented a machine that they don't know how to repair with problems they don't know how to figure out. Is there anyone out there who knows what's going on?