003 charging system problems

alt is over charging,17 vol is to much,should be no higher than 14 vol,probley shorted out the battery,replace both,and get a lower amp alt.

i went and got the alternator tested and was told it worked fine. it didnt over charge at all for the guy. he suggested that it was a lil plastic harness clip. bought a new 1 of them and truck ran fine for another day. now the battery light doesnt come on but i can still hear the fan kick out and the battery gague drop and then the fan kicks back in and the battery gague goes up to normal. we have kept checking the alternator and it has not charged again at anything over 13.8 volts. im happy battery light stopped coming on and truck hasnt died again but im stuck on what could be wrong....im being told all works good now.....

that all sounds normal,the fan is supposed to come on and off,,sounds like you got it fixed.

I just had a similar issue this week with my 2003 Ford Explorer. Monday morning, while driving to work, the abs light came on and the battery light started flickering on/off before the battery died and the engine stalled. I had a garage look at it thinking that it was likely not just the battery. Their prognosis was that it was a bad battery cell. The new battery seemed to be charging from Monday night until Thursday evening when, on the way home from work, the exact same thing happened. I put the new battery on a charger, and it was within normal voltage range. Any ideas on what can cause this? Is the alternator ECM controlled?