I have a 1998 F150 5.4 v8. I was driving around town and noticed the battery light comming on and off. I took it to Discount Auto Parts, and they tested the battery, said it was bad. I bought a new battery, but the light still came on and off randomly, then drained the new battery. As I coasted into Autozone, (couldn't make it to Discount), they charged the new battery, tested it and said the batter is fine, must be the altenator. I replaced it and the serpentine belt while I was there, and no battery light came on any more. I thought it was fixed. I drove it to the store and back (20 miles) and the batter was dead again. What else could cause this. I replaced the battery, and alternator. Voltage regulator? Any help is much appreciated.

 

Did you check the cables? The battery cable to the alternator could be bad.

 

Jaffeld,

Guess any number of issues could be the cause. But I have had rebuilt alternators that were worse than the alternator it replaced. What is your guage telling you.

I think there is a pretty simple test that most garages can do in a few minutes. A meter is put on the battery while the vehicle is running that displays the number of volts that are being sent to the battery. I believe the proper reading is 14. If less than 14 volts are being sent to the battery it will discharge pretty quickly.

 

I'm not sure where you are from, but Auto Zone, Advanced Auto Parts, Sears, etc... around here all perform complete charging system checks free. It's a fairly simple test that takes about 5 min. and will tell you everything you need to know about the condition of your charging system. I would have that done before you throw any more money at the problem.

 

i have a bronco II and, today i noticed that my battery was draining, it has never done this before and then my light came on, and it was getting harder and harder to start, tonight i went to a party and it barely started and i drove it home, and killed it and just for kicks tried to start it again, and it just went gruh gruh gruh. i have a new battery, and i checked connections, but it's kinda dark, what else do you recommend? i need the truck by monday.. any help would be great.. thanks

 

For sure, if you need it for Monday, charge it over the weekend. Then, as posted above, take it for a free electrical system check. Most places that sell batteries do this. Even Wally World.

 

Check ALL the fuses, in the max fuse center under the hood, and i think under the dash. Goodluck

Dave P

 

tonight i was told by my manager, that his mustang did the same thing and he replaced everything, alternator, battery, wires except cyllanoid and when he changed it out everything charged up, i drove it to work, and as i was driving home tonight, my headlights were dim, so i turned them off, and then everything started freaking out, like my antilock brake light came on the check engine light, and my battery light was on, then the check oil light came on, and my computer was shutting down, and i couldnt go over 25 and it made a whole bunch of guh sounds really fast like my engine was shutting off, and then it turned off and i had no power brakes or steering, and then i had to push it home which was only about half a block, so i've put the charger on it and im going to try to start it and run it up to autozone.. thanks for the help

 

I found the problem today, the belt for fan/ alternator was gone, i found a few shredded pieces stuck between some of the belts that were also down there, and they're about to break also. So I'm going to go to autozone and pick up the belts.