2004 Expedition 4x4 lost all electrical

[kbrehbay]

I was driving home late afternoon. Stopped at a red light and all electrical; guages, radio, fan, message center, AC, etc went out. I was able to drive the last 5 miles home but the truck seemed to hesitate when I would pull out. I put a meter on the battery while still running in the driveway and read 7.2 volts. Turned it off and it will not restart. The alternator was changed 3 years ago and the battery is only one week old. Any ideas where I start?

 

[tonydiv]

Sounds pretty alternator-ish to me. Although it could just be the wiring to / from the alt also.

Also, just because a battery is 'new' doesn't necessarily mean it is good.

Throw a charger on it overnight and see if the voltage comes back up.

Then I'd start it and check the voltage at the alt and at the battery. If neither of them are 13.8, it's new alt time.

 

[ELVATO]

Is the replacement alternator OEM or a reman from Advance/Autozone? Does it still have warranty?

Do as suggested above by tonydiv, though I too am inclined to say alternator. You can have both battery and alternator tested at the auto parts store.

 

[kbrehbay]

Replaced the alternator with OEM and problem solved! The message "check charging system' that has been on since the last alternator change even went OFF this time!!!