Hello I have a '75 280Z and the only way I can crank it is with an external start button, it cranks and sparks with the button. I want to start with the key. Can any one explain how to diagnose the Saftey interlock system? because I feel that the saftey system is the problem.
thanks,

Randy

New "Z" owner

I have had 13 Z,s and never had a safty swicht on any of them. You might want to get a new igniton wire set. Trace out evry line and see where they go due ground tests and continuity tests. If you can strat with a button it sounds like a ignition switch issue unless the previous owner put in a alarm system of some sort.
GOOD LUCK and welcome the fantastic world of the Z. You will never drive any other car the same.

I have had 13 Z,s and never had a safty swicht on any of them. You might want to get a new igniton wire set. Trace out evry line and see where they go due ground tests and continuity tests. If you can strat with a button it sounds like a ignition switch issue unless the previous owner put in a alarm system of some sort.
GOOD LUCK and welcome the fantastic world of the Z. You will never drive any other car the same.

I have had 13 Z,s and never had a safty swicht on any of them. You might want to get a new igniton wire set. Trace out evry line and see where they go due ground tests and continuity tests. If you can strat with a button it sounds like a ignition switch issue unless the previous owner put in a alarm system of some sort.
GOOD LUCK and welcome the fantastic world of the Z. You will never drive any other car the same.

I have had 13 Z,s and never had a safty swicht on any of them. You might want to get a new igniton wire set. Trace out evry line and see where they go due ground tests and continuity tests. If you can strat with a button it sounds like a ignition switch issue unless the previous owner put in a alarm system of some sort.
GOOD LUCK and welcome the fantastic world of the Z. You will never drive any other car the same.

I have had 13 Z,s and never had a safty swicht on any of them. You might want to get a new igniton wire set. Trace out evry line and see where they go due ground tests and continuity tests. If you can strat with a button it sounds like a ignition switch issue unless the previous owner put in a alarm system of some sort.
GOOD LUCK and welcome the fantastic world of the Z. You will never drive any other car the same.