This may some how relate to my last post. On start up (hot or cold)the belt(s) let out a horrendous squealing noise. Isuzu95 posted about something similar, but I'm not ready to start a big project. Daily driver, so I need to keep my work on it to from a few hours to a day at most. Here are the exact symptoms. On start up the squeal sounds to be coming from either the upper or lower pulley on the engine, but it is intermittent, it just goes away, then will come back. I'm leaning toward the alternator because it happens under electrical loads (no A/C Trooper) but the noise is not coming from the alternator area. Using the factory gauge as a reference, the electrical output drops below 12v, probably close to 10v, and slowly climbs back up to just over 12v. At this point the noise stops. But turn on the heater fan to high, or the lights and the voltage drops below 12v again and the squealing returns. Tonight I was driving and everything was good, hit the brakes (brake lights) and the squeal came back. Drove about a half a mile like that with the squeal until the headlights and dash lights became noticeably dimmer. Pulled over, shut off the lights and after about 2 minutes the volt gauge crept back up and it stopped. Isuzu95's post was about a similar noise under loads (but associated with his a/c and power windows) and it was the harmonic dampener. I've read about doing a "full field" test but I'm not comfortable enough yet with this vehicle to try it (also I need it to get to work, not to mention parts). In the morning I was going to try and loosen and re-tighten the the alternator and make sure the belt is aligned and the tension is correct. Then test it on the drive to work. Any help or other ideas? Specs are '92 Trooper S, 210.000 miles, 3.2L, SOHC, 5sp, 4X4, auto locking hubs, no a/c, no power nothin' except brakes and steering. P.S. If anyone knows of an Isuzu specialist in SoCal, Orange County area, let me know.