need a 2001 chevy tahoe wiring diagram for the starting components?

[Bri]

We are working on a 2001 Chevy Tahoe with an Automatic Transmission. We are unable to get the vehicle to start and have narrowed it down to the starting components. It will randomly start, but we believe there is a short where the vehicle senses the vehicle is in the "park" position (park sensor) or a problem with the wiring with the ignition. We know the problem is somewhere between the key and the starter. Any info on how to fix this problem or where I can find a wiring diagram would be very helpful.
Thanks!