Ok, in what way are you getting no power to the starter? Do you have power to the headlights? Do they dim a bunch when you try to start the vehicle? Is the starter clicking but not starting? Will the vehicle start if you jump start it? All electrical problems of this nature should start with a load test on the battery, even if it seems fairly new. If it tests good, the next thing I would check is to see if the headlights dim when you try to start it. If they dim I would check the cable connections to the battery, then have the starter tested. If they don't dim you could either have a problem with the ignition switch side of things or the starter solenoid.
3 reasons either the starter is not getting power from the solenoid, solenoid is not getting power from the battery or starter is burned up.
Remove starter and bench test See if you are getting power to starter
the starter isn't getting power or the battery is dead. do some tracing of the power and see where it isn't getting juice
You should check the battery if it is good. Try checking to see if the power is getting to the starter when you push the button if not it might be a falty relay .If power is getting to the starter (12 volt . If less check power going into your relay ) starter may need to be replaced or repared.
Does the engine crank over?
Check your Starter relay to make sure it is getting power if it is cceck to see if the decoder is getting power if both are getting power follow the starter wire to the starter selinoid if it is getting power then check all fuses and ground wires to make sure that it has good connection be sure to check the maix fuses also
Sounds like a defective starter, but check your battery cables and connections. Make sure you are getting power at the starter when you turn the key to the start position. Could be a relay too.
Check to see if power is getting to the starter. If it is not check the solenoid contacts in it may be burned and not letting the power threw . If power is making it to the starter it maybe your brushes are in need of replacement or (dirt in starter ,broken magnets ,bearings or burnt wires).
If the lights in the car come on, then at least part of the system is getting power. Check the battery connections again. Then check the starter solenoid and starter to insure that they are getting power and are working properly.
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.
Check the wiring for the starter, and the starter solenoid for problems. One of these could stop power from getting to the starter.
If the starter does not turn then it could either be bad or not getting power. If a volt meter can not be used to determine that voltage is present, then the starter can be pulled and taken to be tested.