I have replaced the Igntion, regulator, silinoid, and starter. My 66 Mustang, straight 6 will start if I cross the siliniod. I can turn it off with the key. When I engage the key I get a clicking at the voltage regulator (normal) then nothing. I attempted to start it in park and nuetral with no success.

I have read alot of these blogs and have attempted everything. I've checked and rechecked proper wiring etc.

What do I need to do to get this to work. Any other ideas.  

You may have a bad neutral safety switch (NSS)or ign switch.  Directly out of the firewall (it is a 2 or 4 pin connector  near the middle top of the firewall) is a connector, disconnect it and install a jumper wire across the start circuit. Try to start the car (be sure your in park please) If it starts, its the NSS or its adjustment. If not, you need to get the test light out and see if the ign switch is outputting voltage upon start. if it is it is another bad solenoid or it's not properly grounded.  

Thanks I will see if this works.  

Gotter, I did what you said and it did not work. I started tracing back wires to the starter. I had one bad connection that broke when I tried to remove it. I replaced it and it worked. Thanks for the information!!!!  

I have replaced the igntion regulator siloinoid end coilcondeser end contacg points my66mustang straigth 6cyl i cant turn it on