Hey guys. My wife has a 2001 Expedition Eddie Bauer with 5.4 engine. Right at 100,000 mi. Last night she called me and said the battery light was coming on. She was only about 3 mi. from home, so I told her to try to make it. She called back, and she only made it another block or so. Said it just died. I get there and it fired up. All the dash warning lights were on...check engine, abs, battery, etc. All of them. It kept running and in about a minute, the headlighrts went off, then the radio quit working. About a minute later it died again. Nothing. No lights, wouldn't crank. Went over there this morning and it started. All the warning lights were still on. I'm afraid to drive it home, as there is no place to pull off the road between there and my house. I'll get it towed. Has anyone else had this occur? I know that alot of problems with these vehicles is re-occurring. I thought if it happened to me, it's happened to someone else. BTW, back in 2005 I had the blower coming on for no reason, battery draining, etc. I had the windshield resealed and it fixed the problem. Also, replaced the battery about 9 mos. ago, and TPS about 6 mos. ago. This really doesn't sound like an alternator, does it? Why would it start up after being dead earlier? Weird.... Thanks, Ray

 

Have you checked the cables for tightness and resistance?

 

No, I haven't really checked anything. I didn't really know where to start. I guess that would be a good starting point. I did check to make sure she didn't throw/break the belt. It looked fine. It's 3 degrees with wind chill at -10, so standing outside for long periods, checking this and that, is something I'd like to avoid, lol. I guess it could be the cables. I replaced the neg. cable and terminal when I replaced the battery. It's worth a shot. Thanks

 

When the PCM sees insufficient voltage, it starts shutting down non-essential units that consume large amounts of electricity to try and keep it running. Therefor the heater blower motor, the sound system, the headlights? would be shut down as required in order to conserve electricity. (Although I would think the headlights would be considered essential.)

Check the battery's reserve capacity and the alternator's output.

 

It sure does. The alternator went out and you were running on what was left of the battery. Once the battery was drained, the truck is as good as a paper weight. Replace the alternator and charge the battery, and itll work wonders.

 

fun_suv.... at first I thought it was the alternator. But, after the truck sits for a little while, it will fire right up. The battery is strong at this point. It will run for about 2 minutes, then stuff will start dying, i.e. radio, heater, lights etc. Then in about another minute, the trucks quits running. It acts as though it doesn't even have a battery in it. I let it set overnight, went out this morning, at about 3 degrees, and it fired right up. Same deal as before. Also, while it's running, all the warning lights on the dash are lit. Brake, Battery, Oil, Check Engine, etc. It has me stumped. Ray

 

Do your instrument panel lights (the green light) get brighter than usual at any time? Usually when you get all the warning lights turning on at the same time, its an alternator related problem.

When my alternator started to go bad, my gauge needles all dropped to zero, then maxxed out and all the lights got brighter than normal. All of that happened while driving. Everyones experience with the alternator is unique. I say change the alternator to eliminate it from troubleshooting.

 

I'm certainly not saying it's not the alternator. I jusdt can't wrap my mind around the battery being dead, then after setting awhile, it's as strong as ever. I would tend to believe, that if the alternator was draining the battery, then the battery wouldn't "charge" itself after sitting awhile. It makes me think that the battery is not dying at all, it's something else electrical.

 

The alternator isn't draining the battery. The alternator just isn't charging the battery. Running the truck is what's draining the battery.
When the truck stalls the battery is out of juice. When you let it sit for a while, the battery recovers, but only enough to let it run for a few minutes. Like fun_suv said, replace the alternator, or as pdqford said, at least have the alternator's output checked.

 

Get a voltmeter and check the battery voltage when you have let it sit overnight. Then start the truck up and again check the battery voltage.
If you get a initial voltage of say 12.5 with the truck off and then with it runnign you get anything lower than 12.5 your alternator is done. If your running voltage is say 13.5-14.5 you have a electrical gremlin.

I would say your alternator is done. Batteries, especially when new, have the ability to regenerate.

 

I agree that strange things happen when an alternator goes bad. Another thing to try is to charge the battery and see how long it runs for. If it runs for longer then I would say it is an alternator. I do believe that batteries do regenerate themselve to a limited extent when rested.

 

start the truck, then disconnect the battery, if it still runs isnt the alternator ok? if it dies you know its not producing the spark necessary and its running off the battery? just a thought.

 

Don't disconnect the battery while its running! That is a good way to take out the diodes in the alternator.