OK so let's step back and make this "simple." 1...Power comes out of the ignition switch in "start" 1A.Goes through the ignition switch connector 2...It goes through the bulkhead connector 3...If you have it / had it, the starter signal goes through the reset device for the seat belts above 4...The power next arrives at the "push on" terminal of the start relay, goes through the coil of the relay 5...And appears at the remaining push on terminal, which is hooked to the neutral switch 6...This goes down and is grounded by the neutral switch. So, each one of the items 1--6 is a trouble point. 1.. You might have an ignition switch "going away." 1A...The switch connector might have a problem 2...The bulkhead connector might be corroded 3...If you have the seat belt relay BYPASS it 4--5...Could be the start relay (originally, I guess you've eliminated that but remember the TERMINALS) 6...Could be a bad connector at the neutral switch, bad switch, linkage out of adjustment, or problems INTERNALLY with the lever / comb in the transmission. ================================= WHAT I'd do. Since you've had so much trouble, you might try and "rig" some test "stuff. Run a small wire.........this can be very small.........through the firewall to the interior and "rig" a small 12V lamp, just hang it under the dash where you can see it. 1....Run it to the start connection at the start relay. You can, IE get some flat male / female connectors and make up a short "Y" connection so you can hook it right up Now just watch the lamp EVERY time you start the car. If the light shines, and the car does not turn over, the start signal IS getting to the relay and it's "somewhere else." 2...Pull your lamp off and hook it to the remaining push on terminal. Again watch the lamp. THIS time it should NOT light when the car turns over. This shows the relay is GROUNDING through the switch, and the relay should work. A....So if the light shines and the car does not turn over, it's a problem in the NSS end B....If the light DOES NOT shine and the car DOES NOT crank, then it's in the relay / solenoid wire / starter solenoid.