[Velox]

Your Tremec neutral safety switch is a plug with two electrical pins extending out that is located on the driver's side of your trans and, if your car uses wiring for this, there will be two wires coming from a wiring harness and plugging into the pins on the trans switch. It is just an on/off switch, provides continuity when the trans is in neutral. Remove the two wires from the switch, jumper between them with a short piece of wire, and that defeats the switch. It should now start (if that was the problem) whether or not it is in neutral. If that doesn't help (or your car isn't wired for this switch) then it probably is the ignition switch has a loose connection or there is a wiring fault (loose wire) somewhere.