hello all i have a question and help would be greatly accepted. i have a 1991 300zx 2+2 5speed lhd and it wont start up. ive triple checked my wiring harness also grounding points, replaced the starter relay(i have 3). the starter relay makes a click when i try to start it. everything else works fine lights radio ac etc...the motor doesnt move when trying to start the car but the starter makes a CLANK noise when trying to start it. battery terminals are clean of rust. What are some things i should be looking to check or replace? possible causes?????? wont crank