2003 ford expedition

[Terry Derrer]

Battery light on and check charging system battery good and alternator goog

 

[Hamfisted]

Is it the original alternator ? The stock alternators are usually the 110 amp rated ones. Sometimes people try to put a heavy duty higher amp output than the PCM expects to see and it will trigger the warning light. I don't know if that the case in your issue but just something to look out for. Don't buy an alternator from Advance Auto either. Stick with factory Motorcraft or NAPA parts. Are the battery terminals and cables in good shape ? No corrosion?

 

[Terry Derrer]

It is a 135 amp from carquest

 

[Don Hall]

I know you posted the altenator was good. Just check again (?).

https://www.2carpros.com/articles/how-to-check-a-car-alternator

 

[Terry Derrer]

Alternator is good

 

[Hamfisted]

Did you just recently install this alternator? Everyone I've seen who installs a 135 amp alternator in a 110 amp application gets the Batter Charge warning light. You would only have the 135 amp alternator programmed into the PCM if you have FACTORY navigation installed. Very few Expy's had that optioned out.

 

[Terry Derrer]

Can you reprogrammed the pcm

 

[Hamfisted]

Well CarQuest is right up there with Advance Auto as far as parts quality. Do you have a NAPA store in your area? Or order a 110 amp Motorcraft from Rock Auto.

 

[sjwelds]

Motorcraft only on alts

 

[Yupster Dog]

Had Duralast (Auto Zone) alternator in a few vehicles (including present truck) never had a problem after. New not reman.

But if I did there was lifetime warranty. Easy to change out so I had no worries about having to take out twice. But never had to.