Well this is my first post, and I likely won't have many since I am not fortunate enough to own a vehicle as nice as a Trailblazer. I am on vacation in Las Vegas, and my dad who is fortunate enough to have an 05 Trailblazer 4.2 has developed a problem. This only has about 33k on it. It has a whine. Now I did read the post that was posted about this and what the person found, which was an idler pulley. I would like to describe the sound and see what you guys think. To me it sounds exactly like an alternator that has a short in the stator, an electrical short. I am familiar with that sound as I used to work for a place that specialized in alternators, starters and batteries. We did testing and repair. However I unplugged the alternator and started the vehicle and the whine was still there. There is no problem with the voltage either on the meter or at the battery (checked with volt meter). I'm hesitant to say its the idler pulley as the whine varies in pitch with the changing of the rpms. If it was the bearing I would think that it would have seized by now, as my dad stated that its been doing this for quite awhile (months). I've never known a bearing to last much more than a couple hours tops when its about to go. I'm hoping its something simple. He has limited tools, though I'm good at improvising. I don't really want to randomly start messing with crap as its been averaging a balmy 111 degrees and I'll be working in the heat. This whine does clearly come from the front of the engine on the drivers side. Any input would be appreciated. We are here for a few more days and really would like to get this thing going so we can get the boat to Lake Mead and do some fishing for Striped Bass. Much thanks, and sorry for the length of post.