Starting probelms help please

Well after 3 days of crawling around under the dash I decided to check the seatbelt interlock voltage. When I held the ignition switch on I checked each wire with a test light. When I touched the forth wire over a brown 20 ga wire the car turned over and started. After checking the wiring diagram I found this was the NSS wire on the interlock. Just crawled under the car and checked the new NSS to see if it has continuity and it does. So tomorrow I will start check all the wiring and grounds to the NSS and hope thats the probelm.

We did take out the instrument cluster and clean all the conections and the AMP meter does work I already jumped that to see if it was the probelm. Hope all goes well tomorrow and we get his car back on the road.