'89 Cadillac DeVille alternator question

155,000 miles. Daughter called just before Christmas and said that alternator light had come on and the engine died soon after. Son gave her jump and she got about 2 more miles. Battery one year old so it sounded like classic alternator problem. Battery dead so I picked up rebuilt alternator from Pep Boys and installed myself. 5 days later daughter called and said same thing had happened. Several people told me alternators are not rebuilt as good as years past so I replace alternator again and get charging system checked out. They say alternator and battery look good. Now about 3 weeks and daughter says car has not died but about every 2 days the alternator light blinks for about 30 seconds and goes back out. Another check of system shows everything good. Does this sound like another bad alternator? Any advice welcome. Hate to have daughter broken down on road at night. She has started turning off all accessories such as defroster to decrease load for now. All I can think of is to check wiring between battery and Alternator to check for possible intermittent short. No fuses blown either time.

Thanks in advance.

it may be dirty connections. from the battery to the starter, then to the alternator. look at theconnections and make sure there is no corrosion on them. if there is, use a wire brush and clean them then see if the light keeps coming on again. another possibiliey is the regulator inside the alternator or even a rectifier(diode) could cause the ittermitate problem.

Cleaning the connections at the alternator fixed the problem. Never had that happen before and I have replaced several alternators over the years. Thanks for the help.