GM-GMC: Engine replaced, gmc sierra, fuse box

Question
Hey i replaced a my engine in a 1998 gmc sierra i put it in and wired it up but when i turn my key to on all my warning lights come on and when i push it to start it dosent do nothing. I have checked the starter and wiring it on good also sometimes when you hit the brake all the lights go on and the door buzzer goes off and a relay starts clicking in the engine fuse box what could be the problem.

Answer
Wow.  Something is definately wired up wrong.  It would be pretty safe to assume that none of this was happening prior to changing the engine.  Double check all of the wiring that you had disconnected and then reconnected.  To be quite honest I have no idea what would cause lights and buzzers to go off when you hit your brakes??!!  I have no easy fix for this one, you will have to slowly retrace your steps and double check things one by one.  
Hope this helps.