2000 Chevy Express Replicing silinoids

There are two wires going to the solenoid. Connect a volt meter to one of the wires and the other lead to a good ground. You should see 12 volts DC. If not, connect to the other wire and a good ground. If you still don't show 12 volts, check the trans fuse. If it's good, replace the ignition switch. If you do have voltage on the solenoid wiring, replace the solenoid. Push on the shift valve to make sure it's not binding in the valve body.