I have a 97 expedition with a 5.4 in it. The alternator started squeaking so I replaced it. The replacement also squeaked so I returned it and had it bench tested..it failed. Got the next and the same. Figured tension wasn't right so I also replaced the tensioner to no avail. Is it crappy alternators or any ideas would be great. Thanks

 

I have an idea and it may not be what you want to hear, but Ford alternators seem to come with their own problems which I have found are generally eliminated by getting replacement alternators from Ford ! It may cost a little more, but there is nothing like doing the job over and sometimes over again. Chances are the tensioner needed to be replaced anyway so that was a good move. If you had a rebuilder locally that would have been a good move to have them do your old alternator. Let us know how you make out with this,thanks.