I recently bought a 2002 Isuzu trooper. There is a strange noise coming from the vehicle, it sounds like it is coming from the front. While this noise was going on, the alternator went so originally we thought that the alternator was responsible for the problem. However, after replacing the alternator and the battery the noise is still there. When the alternator was replaced there was a lot of burnt wiring that was replaced also. It's kind of a hard noise to describe. It sounds the same as when you drive over those rumble bars at the side of the road but without the vibration. It only happens when driving the vehicle over 30mph, but when the vehicle is in park and the engine is idleing the noise doesn't happen. The transmission shifts smoothly and the engine seems to run perfectly. I'm wondering if it is some kind of electrictrical problem. Any ideas?