Help I got no Juice

[69CamaroRacer]

Today was Saturday so I decided to get up early and spend the day workin on the camaro so that I could drive it to work tonight. So I have been installing electrical gagues for the water temp and oil and volts. I also just installed a newer style CS 180 amp alternator. When I was putting the new alternator in I found some old wires in the origional harness that were burn and looked like that may possible cause a short so I cut the bad sections out and replaced them. Then after everything was hooked up I started the car and it ran fine and it was charging measured around 13.5 V. Anyway long story short after it ran a while I let it sit to cool off and then I went to try to start it again but nothing happened... no clicking no nothing. I have interrior lights and headlights but no start. One thing that i did not do was I did not install the Dioad inbetween the alt and the MSD Box. I knew I was supposed to and I orded a kit from Mad Electrical but i still haden't arrived so I ran it anyway. I was able to start it and run it several times with no problems and then today nothing.. Is it possible that I fried the MSD box? I checked and I have voltage across the msd coil and I can hear the capasitor charge up inside the MSD box when I turn the key but that is it... So no I am at a loss as to what to do. Help!

[derekf]

No start - won't crank or won't fire?

If it won't crank, confirm you've got power to the two terminals on the starter when you turn the key?

If it won't fire.. what does a timing light do when you try to crank?

[69CamaroRacer]

Problem solved It was the Nutral Safety switch.. I must have accidently knocked it loose.