It appeared my truck had a dead battery. I got a jump and drove it for about 20 min. Shut it off and tried starting it again right away. It appeared dead once again. I thought the alternator wouldve charged it by then. Tell me what ya think.

 

Well, both the battery and the alternator can be tested to see if they're good.

 

did you clean the battery posts?

 

when you drove it did you have lights on and could you tell by the gauge if it was charging ?

 

Head to Autozone/Advance to get a free charging system check.

 

yes, possible start problem, autozone or the big companies have a machine that will test your battery, your alternator, and the current draw from your starter. This is usually a free service, but to check the starter you may need the jump vehicle handy.

 

take off the alternator and take both that and the battery in to autozone. They can test them both. the battery may not be holding the charge, the alternator might not be putting out enough current, or the alternator might be back feeding the battery to the point it is to dead for the alternator to charge it enough to start again.

 

get a $5 multimeter.........jump the truck........if the alt is putting out over 14V at the most likely it is the battery........if you have an interstate battery office around you can buy new "blemished" battery for $40 with a 2 year warranty

 

agree with powersmoked, check the alternator output with a multimeter and if it checks out over 13.8 v then most likely the battery is toast. you could then take the battery to autozone etc and have them do a test on it.

new batteries also can be bad-
i had a cell in a 2 month old exide battery fail in my daughter's escort ..
thanks exide

 

If you get a new battery and you have a charger, put the new battery on the charger over night slow charge..... Had a friend who worked for Firestone, he said a lot of the batteries they installed off the shelf came back in a few months, the ones fully charged lasted longer than most people kept the vehicle.

 

My battery recently went in my 2000 Ranger (amazingly, it was the original battery with a Feb 2000 born-on date). I replaced the battery an things appeared to be right, but I noticed the battery light coming on and then going out after driving for about 5 minutes. I watched this over the next few days and what I noticed was that the battery charge was dropping. Eventually, the battery charge got very low and the dash idiot lights lit up like a Christmas tree (on Christmas Eve of all days). It ended up that the alternator was toast and wasn't charging the battery (the battery light is and indicator light for the charging system, not just the battery). The tech at Ford told me that in his experience, the battery and alternator wear-in together, especially when the battery is as old as mine was. Typically in this instance, they would replace the alternator and not just the battery. When you put in a new, fully charged battery, you'll pop the alternator. Keep this in mind in case it is your battery and in the case that your battery is a fossil like mine was. You don't want to get stuck.

Good luck!

 

junkyard motorcraft alternators go for $25 around here. i have had one in since sept/08 and still working