Bring my 73 dart swinger back to life.

Update
Connected the battery. Won't start with the key. Will start with hand trigger on the solenoid. Couldn't find my test light. Looked everywhere. It was at the house in the Vette.:banghead: Where would the best place to start. In the engine compartment and work my way into the cage under the dash. I'm not an electrician. I usually find the problem after a few times 3 tries. I adjusted the shift linkage so it would go into park so the key will come out. Just a point in the right direction. Maybe someone has had this problem before.:coffee2: