Check your ground wire from the battery going to the engine by the starter. Also check both wires connecting to the battery. If the wiring is ok it might be the starter solenoid. Open up the box where the Red wire from the battery goes to, and jump across the solenoid to see if the starter turns over. Use a 14 guage insulated wire. If the starter turns over now, it is the starter solenoid, replace it.
Karl