Ok so heres whats going on. I have blazer 4.3 4x4 the other night i went to turn my truck off and it wont die all the gauges would go off but the motor kept running. Called a buddy of mine who works for gm and he said it sounds like the igintion switch has messed up. So I got one and put it on now it wont start and i can hear a clicking sound under the dash but the starter isnt turning over.All the gauges are working the fuel pump is priming but nothing!!!!! Can anyone give me an idea of what could be wrong im lost at this point.

 

It is a flat out guess but I would say you have activated your VATS security system by removing your ignition switch. Does the security light on your dash flash?