93 Bonneville Electrical problem

The short version of my problem is my car keeps turning off due to lack of electricity for some reason. It will turn off and not start sometimes while sitting in the driveway, and sometimes driving down the highway in the left lane in solid traffic while going 70MPH (that was really fun).

Just to warn you, I am long winded. I give anyone full permission to make fun of me if you can only help me fix this stupid problem.

Here is the whole story of what's happened:
The first time I started having trouble, my car would sometimes just not start. Eventually it would stall periodically while running. At first, I would try to jump it off because it seemed to be symptoms of a dead battery. But usually it would start when I tried one last time before hooking up the jumper cables. Finally I noticed the positive battery cable seemed loose, so I cleaned and tightened the connection. It worked for a while and then started doing the same thing. At one point, I replaced the battery and alternator because both of them tested bad at O'Reilly's. That also helped for a while, and then the symptoms came back. I noticed at one point when it was having the worst times starting, the battery post was really hot. I finally decided to replace the positive battery cables because they were getting black and I was hoping that was the problem. When I took them off, the wire going to the alternator was broken and barely connected. Everything seemed fine for about a week, and then it started showing the same symptoms once again. If anyone has any ideas, please help me. I have already come within a foot of hitting a car at 40MPH due to my antilock and power brakes shutting down in the rain due to lack of power. I would really love to fix this problem as the car is still in really good shape other than the fact that it randomly shuts off.

Josh

I replaced two alternators on my mother's '93 Bonne.

Time line went like this:

Alternator failed. Replaced alternator. A week later Symptoms reappeared. Battery was original so replaced battery. Two days later symptoms reappeared, had alternator tested, bad. Replaced alternator. Three years ago and counting.

GM seems to have had alternator issues for a long time. I replaced alternators on my Bonneville, my mother's, a friend's Grand Prix, and my ex's Sunbird.

What I don't understand though is both my battery and alternator are testing fine now. Since I replaced them, they haven't tested bad.