Hi, i'm new here, so please bear with me. I've got a 2000 Expedition and my battery warning light came on yesterday while driving through some pretty heavy rain. My first thought was that maybe the electrical system got wet. I let it dry overnight and the light is still on. Does anyone have any ideas as to what i can do to fix this? My battery gauge on the dash still is at 50% and hasn't moved one bit throughout this whole ordeal. Thanks!

 

Ok, i just did a quick check and the battery voltage (car off) is at 12.38V. With the car on idle and a/c, stereo, and headlights on, the battery voltage is at 11.9V. Is my alternator jacked up? BTW, my car only has 38k miles on it. Is this normal for an alternator to go bad this soon?

 

There are pinpoint tests you can do to determine what the exact problem is. Do a search or go back a couple of weeks here.

 

It does sound like the alternator. If you want to take it off yourself, you can have it checked at the store to make sure.