Hey guys i have a question for you.... This morning and for the past couple months my battery light would sometimes come on and flicker on and off. I noticed it seems to go away when i rev my motor up going down the road.

I also noticed the other night when i was sitting in my driveway that my dash and head lights would get dimer then brighter, and just go back and forth.

I checked the voltage when the light was flickering and it was normal at around 13.5 to 14. My voltage gauge in the dash had never droped down during all this either

Any help on this would be awesome. Thanks

 

Check ALL the connections & wires first (alternator & batteries) -- clean & inspect. If it still comes on, have the alt tested and if you can, watch your batt voltage starting now so you can get a baseline of what's going on.

 

Agreed, I would say 9 out of 10 times this is telling you your ALt on its way out. But Like Joe said, check the connections, in patticular, the plug in.

 

Agreed on the Alternator thing.

My Battery light came on, replaced the alternator, good to go.

 

This is typical symptom of the brushes in the alternator are getting to short to make contact with the slip rings. With all the trouble with replacement unit, I would recommend having your original alternator rebuilt at a local shop.

 

Replace the alt. Does it usually come on when the truck is warmed up or any givin time? If it only comes on when its warm. Take it down and get it tested, and make them hit it a few times to warm it up. If still in question ask them to test a new one and see if there is any real differance in the read out, and compair the results.

 

Same thing happened to mine... It was just one of the 2 wires that come out of the top of the alternator was rubbing on the alum housing and exposed the copper wire just down from the connector... fixed it.. been good for two years now..

 

I'm not saying you dont have a problem but I've read on several occasions where batteries and alt were good and the light would flash or stay on. The problem ends up being wires chaffing. So get the alt and batteries tested before throwing parts at. My freind scott has had his light on for 2 years now and still waiting for something to go out.

 

But, even if you test the alternator, and the wires arent making a good connection, it is going to look like the alternator is bad, correct? My battery light just came on today, is solid on and flickers a little bit under hard acceleration. I am going to start checking the connections first.

 

What Joe said in Post #2 is correct!!

FIRST... Tighten and Clean ALL connections on batteries and alternator (even the battery ground connections on block/frame, too)... even if they "look good"... tighten them.
SECOND... Ride around to see if symptom goes away.
IF SYMPTOMS REMAIN... have the alternator checked and replace if bad.

 

Put a volt meter on the battery/s while it is idling... should read about 14v.. If the meter says something like 12v.. your alternator is probably toast..

 

If you have more than about 135,000 miles on the truck, there's a good possibility that your alternator regulator's field brushes have worn to the point they're getting to the end of their physical range, and are not allowing dependable field current.

The slip rings probably have some deep grooves worn in them, too.

All the above says is that the alternators only have so many revolutions in them before they develop a physical wear problem. They're not completely solid state. :-((

On the up side, they're simple to replace!

Pop

 

Well, I replaced my alternator today. Like I said previously, the battery light came on yesterday when I cranked it up to drive home from work. I had never seen it light up before, and when it came on it stayed on and only flickered a little under hard acceleration. This morning when I started it up, it was kind of slow to crank and I knew it wasnt gonna be much longer. So I drove to Napa, and they asked if I had tested it. I hadnt, and they didnt have the equipment to test alternators but they told that the place across the street did. So I decided to have it tested. I went back to start the truck and drive across the street and, lo and behold, it wouldnt crank. Got it jumped from a guy in the parking lot, drove across the street, left it running, they tested it and it was showing 11.4 volts. They would rebuild me one for 165, but i decided to get one from Napa for 209, with a 3 yr warranty. Went back to the shop, put it in and, no battery light! I just bought my 2002 Excursion limited 4x4 7.3 and it has 102,000 miles on it and I am pretty sure it was the original alternator. I guess it had a pretty good life. Problem solved, I think!

 

Now go home and put your battery charger on the batteries to get them fully charged.

It would be a big mistake to depend on the alternator alone to bring them back up to snuff.

Pop

 

2005 F250 Battery Light Flickering. After reading this thread and another website thread and knowing my alternator was excatly one year old I check the wires. Turns out there is a small one wire connector that worked itself loose. Pushed it in and no longer expereincing the battery light flickering. Simple fix that I should have done three months ago. I don't think I have any ill effects. Truck is running fine. Now if I could change the sensitivity of the automatic headlights they would come on and off while driving to work at dawn.