"If the solenoid clicks when you press the start button, you have a faulty solenoid. If it doesn't, it could still be faulty". If it doesn't click, test the thin wires to the solenoid, with ignition and safety lock-outs on, one wire should be either live all the time or earthed all the time, the other wire should get power (live or earth) when you press the start button. If this isn't happening the solenoid is OK and you have to trace the wire that isn't getting power back to where it is broken.