i bought my truck about 2 years ago. no major problems. well tuesday i was driving home and my power for my truck went bye bye. so i took the batery and alternator out and got them tested. battery was good but they told me alternator was bad. i changed the alternator on wed. well tongiht same thing happened the lights started dimming then no power. the battery is about 4 months old. what could be hapening to cause this. could this be a bad alternator?

 

It might be tough to tell if it's exclusively the alternator, if you did just change it.

How is the belt tension? How are hte battery connections?

Does the power disappear immediately, or gradually?

 

Was the alternator a rebuilt aftermarket or a Ford? It sounds stupid, but my alternator did the same thing on a my old truck about four years ago. I went to a local alternator shop and got a rebuilt one. We put it in and two days later the same thing happened. I took it back and they checked everything and I ended up replacing the battery. Two days later, same thing again. To make a long story short, I finally ended up getting an alternator from Ford and the problem completely went away. The Ford tech claimed that they had seen many Rangers with the same problem with non-OEM alternators. To this day, I'm still skeptical, but you can't argue with the results...

 

It could be cooincidence and you got bad replacement alternator. Or it could be something else is wrong and that is how long it takes for the battery to die due to not charging.

 

oddly enough my plug came unhooked and killed my battery a few weeks ago check tht...

 

yes the battery was charged fully for one hour at advance auto part. also bought the alternator form them. the alternator was about 140.00 and was lifetime rebuild one. i will go back up to the store laster today and test the alternator make sure that is the problem again. will let you know what happenes.
thanks for all the responces

 

I drove it 500 feet and it died again. retested the alternator and battery again, and it checked out good. checked all fuses, and none were blown. the belt was good, and tight, and the plugs were all good. all the connections on the battery were good and tight. any new solutions??