How do you tell if starter is getting power?

The best way to tell if a starter is getting power is to use a volt meter. Put the positive lead of the volt meter to the largest ( power ) cable attached to the stater and the ground lead to the chassis. Have a friend turn the key to the start position and see if you get at least 12 volts. If the starter clicks it is getting power and chances are your starter solenoid has failed. Before doing all this it is best to inspect the grounds between your engine and the chassis. Make sure the ends and the places where they are mounted are clean. Make sure the grounds are not excessively frayed as lack of ground will cause the starter to turn slow or not at all.