Does the Dashboard lights Dim/go out when you attemmpt to start it? Do they stay lit when the vehicle wont start?
Have you done the basics, such as check the connections on the starter, and the wires coming and going from there???
I'm not completely sure that your car has the security chip. If it does (and im probbakly wrong and your has it), is it possible that the Ohm load is off? (i believe that they used ohm impedance for the security).. Id check there first.
Does tapping the starter work? I see that you said that the lock/unlock had something to do with it... I have never heard of that one.....
Bill