I have had this problem like a few times, its sparatic... ill turn the truck off, for like,, 2 minutes come back and the battery will be totally dead and would have to jump it.

so when i came home tonight i did a test... i started the truck, and then disconnected the battery totally, and it ran with no battery, so then i hit the headlights, low beam, and bam! just stalls out. now, isnt a vehical supposed to be able to run 100% off the alternator with out the battery?

 

You just answered your own question, time for a new alternator my friend...

 

Have your battery tested, it soungs like you may have a bad cell.

 

The battery was completely removed from the electrical system and yes it should be able to run w/o a battery. You should have your alternator and battery tested though. If your alternator is that bad your battery may be cooked as well.

 

thats kinda crappy that your alt would be going out already.. im still on my original, as well as the original batt. (hope i didnt jinx myself )

 

well in the lil window, the ball is green. we have a load test tester, and it says my battery is good. now dad made me clean my terminals, cause there was a lil bit of corrosion, but even so, the truck should be able to run with the stock options off the alternator right..... dad says alot of the newer vehicals may require a battery, but that doesnt make any sense, since the alternator i think is 100 amps or so...

would autozone be able to tell me if my alternator is working at full capacity or not?

 

Get a new battery..

 

Yeah I'm not sure if they can test it on the vehicle though. I know I took one in off my sisters car and they give you a little report and everything lol.

 

they can test it either on or off the car.

 

just "buy a new battery"? its warranteed for 36K miles, if its toast ill let the dealer replace it.

welp, geuss ill just whine to them, cause my timinng chain is rattling pretty bad now.

 

Well hell, sounds like ford owes you half a charging system; now don't they?

 

definatly the alternator.

Its not 100% dead, as it will still run for a little while, untill you start using more electricity.

autozone will test both on the vehicle, however, when my alternator died, and i drove it there on JUST the battery, they also said my battery was dead, I would replace the alternator first, then go back and have the battery tested after a 15 min drive on the highway.

Also, I have had batteries be completely dead, and wont hold a charge, but put them on a trickle charger overnight, once they are fully charged, they hold a charge again :)

 

Im with these clowns^! deffinatly your alt....and while your at it get the 140 amp one...youll thank me later!

 

Easy to check.

Engine off: check voltage at battery terminals.
Should be 12 volts dc +

Engine running: Check voltage at battery terminals again.
Should be up over 13.5+ volts dc EVEN with high beams on.

If not, Bad alternator.

 

Actually with the engine OFF the battery voltage should be around 12.5VDC.... If the battery is down at 12V their may be a cell going bad.

OR 4x4