Battery or charging system problem??

Do yourself a favor an take it to a qualified repair shop. Charging system is computer controlled , if you have been to school for this ,you have no business messing with it .

probably alternator fusible link
press the helpful button, and check video link below
Fuse link replacement for Ford Expedition 2003 5 4

You checked the charging voltage at the battery with a ? volt meter ? What was the voltage with the vehicle running ? 13.1 to 14.1 volts ?
BATTERY NOT CHARGING The IPC illuminates the battery not charging indicator in the driver information center when the following occurs:
?€¢
The PCM detects that the generator output is less than 11 volts or greater than 16 volts. The IPC receives a class 2 message from the PCM requesting illumination.

?€¢
The IPC determines that the system voltage is less than 11 volts or greater than 16 volts. The IPC receives a class 2 message from the body control module (BCM) indicating the system voltage

Charge Indicator Always On
Step
Action
Yes
No

1

Did you perform the Diagnostic System Check for Starting and Charging? yes or no
Go to Step 2 yes
Go to Diagnostic System Check - Engine Electrical no

2

1. Turn ON the ignition, with the engine OFF.
2. Observe the Charge indicator on the instrument cluster (IPC)

Does the charge indicator illuminate?
Go to Step 3
Go to Symptoms - Engine Electrical

3

1. Turn OFF the ignition.
2. Disconnect the generator connector.
3. Turn ON the ignition, with the engine OFF.

Does the charge indicator illuminate?
Go to Step 4
Go to Charging System Test

4

Test the charge indicator control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 6
Go to Step 5

5

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls 4.2L.
Did you compete the replacement?
Go to Step 6
--

6

Operate the system in order to verify the repair.
Did you correct the condition?
System OK
Go to Step 3

That auto has lots of mini computers to keep everything working. I would try a new battery after leaving the old battery disconnected for an hour. If everything works, run test light to determine if and where there is a drain on the battery.

there is a good chance that the battery is shot may have charged it but if put under load it wont allow enough voltage to spin starter also clean the terminals

Sound Like Transmission Position Sensor ... a sensor determines when you are in Park when stopped...if not, wont start...

Other solution could be Fuse Relay...do you hear buzzing sound coming from fuse box. If so, feel which one is failing and replace. $6 at Autozone....

check battery and charge then if battery shows good (Load Test) the check charging system it will be one or the other ( chg system could be fuse also)

if battery is ok,some times a new battery is bad,have your charging system checked

check heat shield around the cat ...if there is no heat shield ..you should install one

Check the starter relay under the hood in the fuse box.