I've had my truck for about a year now. Only 6K miles. I've had two dead batteries now in the last couple of months. Sometimes I go for several days without driving it and it's during those times that the battery goes kaput. The only thing I can think of is that I have an Edge Evolution programmer that I have permanently hooked up with the display that attaches near the driver's side A pillar. Of course, the display goes dead when the ignition is off. I've had the programmer for 5 months or so, so it's really not fair to blame it for my problem, but the thought has entered my mind.

Is this a common problem? Is the OEM battery that weak? Could the programmer be putting a drain on the system?

Oh...and I wasn't going to mention this because I thought I was going crazy, but I actually started the truck via remote start. I heard the horn honk, honk again, and then I heard the engine crank as well as hearing it fire up and start running. Yet when I went outside about 1 or 2 minutes later it wasn't running. Upon trying to start it, DEAD. I had dismissed this idea and assumed I was imagining things and that I actually never heard it start but merely crank over but... I can't for the life of me think of how the engine would start, then quit, and then have the battery go dead. But then I saw someone else make a post about his battery going completely dead after being in the store for a short time. Weird.

Tony

 

ummm, you have had your truck for a year and put 6k on it?

 

Sounds like the final diodes in the alternator are fried. Here's an easy way to check. With the key off, remove the lead/heavy wire from the alternator. Look for any small arching of electricity. If you have any, the alternator is bad allowing juice to follow back out of the battery thru the alternator to ground. The final diodes are like a one way gate allowing juice to flow out of the alternator but not back in it. This is a common problem with any Ford alternator. If you are going to replace the unit, but only new, not rebuilt. Rare is a rebuilt alternator that the rebuilder actually checks the final diodes. If it makes juice- it passes their test. Same goes for the auto parts houses that "check" alternators.

 

I would think that if the alternator and/or battery is bad, it would be covered under the factory warranty.