After replacing the alternator the battery light comes on and does not charge properly.

 

1. What was the original problem?
2. What year is the CV ? Some alt are controlled by the PCM. and if not checked out thoroughly wrong conclusions can be obtained.
3. Where did you get the replacement alt? Some rebuilders can't get them right.

 

It is a 2003 lx.the original problem was low voltage which I have determined was the regulator. You are probably right about it being the after market alternator not being compatible.I have tried two after market remanufactured alternators with the same results.

 

Speaking for myself, after getting burned a few times with aftermarket alternators for Fords, I will try to get my replacements from Ford and avoid the problems.

 

A lot of alternators can be fairly easy to replace, while some can be real stinkers.
If the proper tools and tests are not done at the time of installation to verify correct output and control , a lot is left up to chance.