I doubt if you have had three bad alternators in a row. If
your battery is being overcharged then the regulator and
associated wiring is at fault. Since the regulator is
attached to the alternator they are changed at the same
time. On some alternators it is possible to remove/install
the regulator. I canā??t speak for the alt in the contour
because (fortunately) I havenā??t had the pleasure on changing
one yet. Double check with the dealer and make sure they are
changing the regulator. If they are, have them inspect and
test the Alt/reg harness.
If all else fails, get your money back and bring the car to
an automotive electric specialty shop.
jeff