The past several days and nights has been an adventure into the field of AZL loco maintenance. It's been a slow, careful exploration into what makes AZL locos run. I've taken SD70s apart, GP38s, SD40s, (a little) and the one causing me grief is my early release version of the UP GP7. She is a beautiful little loco with a slim body, but she refuses to run decently. After thorough examination, dismantling and putting it back together, I understand how it works, and I have come to the conclusion that the bronze strips on the body don't make strong enough contact with the bronze pieces on the trucks themselves. If there were a way to put wheel wipers on it I believe the electrical contact would be better and solve the problem. I've cleaned the track, (and my track work is good) and when testing the loco, it will run for a ways and then stop. Touching it will make it move again, but it stops at any point without reason. I can only conclude the problem lies with transfer of current from the trucks to the bronze strips on the chassis. Has anyone had similar problems with their GP7 and if so, were you able to rectify the problem and what did you do? Wanting very badly to turn this loco into a winner.