Ford Fastback electrical gremlin?? Please help!

[toofun]

But how do I prove that it is a bad ignition switch? I dont want to start replacing parts until I find out what is wrong. There has to be some method to check if this is the case? One thing I did find out is that with the key in the ON position there is no power going to the + side of the coil. I put the key in the one position, put a test light on the + side of the coil and it did not light up. I also disconnected that wire going to the + side of the coil put the key in the ON position put a test light to the wire and still it did not light up. But if that is the case then why does it fire up when it is in the start position? The same wire cant be hooked up to two different parts of the ignition switch? Like I said really need to get someone who knows electrical inside and out to help me out here. It is very frustrating just trying to guess and replace parts...