more than the alternator diode is bad have the alternator checked
what causes the battery light to on a 2005 ford expedition to come on?
The battery isn't being charged
the battery light means that your battery is being charged properly. so let it light.
The battery light comes on when the alternator is not charging. Changing the battery did nothing. Either put a gauge on the battery to see if it is charging, or while running, disconnet the positive cable from the battery. If the car dies that means the alternator is not charging. Most parts stores will check it for free. Oriely's , Autozone, etc.
Check battery connections, check alternator out put. Exc.
If your engine is running , and the battery light comes on , that indicates that your battery is not being charged
Your battery is not being charged
time for a new battery or just the cable is going bad
because the battery needs charged or need a whole new battery
The battery light indicates the system is not charging. Have the charging system checked. If the alternator is not charging, the engine will quit running and leave you stranded.
Defective alternator or bad wiring.
The battery light comes on when the alternator output voltage is too low or too high. You have a wiring or regulator problem.The battery light comes on when the alternator output voltage is too low or too high. You have a wiring or regulator problem.