Does it have a GM colored wiring harness? If it does, the starter solenoid wire is purple. Get a test light and see if there's power there with the key in the START position. If not, keep tracing back until you find power. If you get to the switch and no power, but the switch has power going in, then the switch is probably at fault. If you have power at the solenoid, then the solenoid and or starter is bad.
