Battery light stays on. Stumped?

[_JWO_]

2001 Expy 5.4L battery light stays on. Brand new battery, alternator checked 3 times and is good. One minute battery light goes on and battery loosing charge and alternator not charging at 14v . Next alternator would be charging at 14v and battery taking charge. Dont know what to do runningout of options dont want to buy more batteries and more alternators if i don't need to. Thanks.

 

[stamp11127]

Check the plug that connects to the alternator. They have been known to fail as the harness ages.

 

[Bedrck47]

As stamp suggests

Also read the attached link, about recent similar problem

http://www.expeditionforum.com/threads/battery-light-stays-on-but-charges-fine.31792/

 

[Mattatdelk]

As mentioned above check the connector on the back side of the alternator first.

My next question is...if by any chance you picked up a new alternator was it a parts store special or an OEM ford unit? The past few years I have ran into issues with just about all of the "aftermarket" options on all the 4.6/5.4 mod motor fords..They all tested "OK" but just couldn't keep up with the demand on these fords...

 

[1997SCEBFEX]

great advice above.
what about your cables? corrosion is known to creep backwards and cause bad/faulty connections.

let us know what you find.

 

[_JWO_]

I will try this when i have time and will get back as soon as i can.

 

[_JWO_]

Appreciate the feed back

 

[Boose]

When the Alternator is tested, is the voltage reading taken at the alternator or the battery?

 

[doug-ocon]

I have the same problem with my 2000 . It is a loose connector (single wire) on back of alternator

 

[_JWO_]

Tried cleaning the wires didn't work. Started the car one more time and tapped on alternator figured why not slim chance it might work. Then BAM charging at over 14 and light is off. So question what should i do?