93 Pontiac Bonneville

my security light flashes and my car wont start sometimes it takes minutes, hours or even days for it to stop blinking.  When the security light is steady my car will start and while im driving the light stays on, I have had my car for 8 yrs. and have never seen or new i had  security.  Someone tried to steal my car and  I had to get a new steering collar and blinker switch put on it, I did not put a new ignition switch on it. Can someone pleas help me!