wiring help

I am trying to find key on 12v power? I have a probe light which a clamp to the negative battery post. With the key on, I am probing the two small terminals on the starter relay and nothing lights? I am probing the two field terminals on the alternator and nothing lights. The only way I get a light is to touch the positive battery post. LOL. SO, seeing that the car has had a new total ignition switch and turn signal switch installed, and being I installed an MSD box with an MSD ready to run distributor and also did the amp meter bypass, where the heck do I begin to look to chase the power sources? I eliminated the electronic box and a wrapped wires together on the 4 post ceramic block to discontinue it? Anybody want to take a stab at why I can't find key on 12v sources??