Hey everyone,

I have a 2002 Nissan Pathfinder with a battery drainage problem...here is what I have going on so far...
With the engine running you can hear a loud squeal. Checked all the pulleys, replaced 2 bad tensioner pulleys. Still squealing, replaced power steering pump and alternator (didn't want to mess around with just chaning the pulley on both). Still squealing, just turn the radio up louder to ignore it. One day, car won't start. With no jumper cables, took the battery to napa with a friend, they tested it, said it was bad, bought and installed a new battery that day. Just to be safe, took the car to napa after putting in new battery and the alternator tested bad. Took the original alternator down to napa and had it tested on their machine, it tested good so I put it back in the car. A week later, while driving down the highway for about 20 minutes, all the lights inside and outside of the car start to dim. Pulled over, opened the hood, checked the battery cables, all tight, no corrosion, shut the car off, tried to start it back up, battery was completely dead. Had a friend come jump it, as soon as they took the jumper cables off, lights dimmed again and car shut off. Took the battery to Auto Zone, they charged it, said the battery was good, drove the car home. Drove maybe 1 hour total over the next to days only to have the battery die again. Took it back to napa, they said the battery was bad and gave me another one. The battery does not drain overnight, does not drain while the car is running at idle, as soon as I get on the throttle the battery voltage starts to drop pretty quickly (probably only 20 minutes or less on the throttle and its completely dead) All wires look good, all fuses are good, alternator keeps testing good, everything works, no lights out, no warning lights on...
Does anyone have any suggestions at all? I am at a loss here, especially because electrical is not my strongest area.

Sounds like faulty alternator.

^^Ditto what he said^^