Cadillac Repair: Security light flashes & wont start, starter solenoid, key cylinder

Question
I have a 1993 Sedan DeVille and when the key is turned on the Security Light flashes continually and the car will not crank (note: manual bypass to starter solenoid crank the engine but it will not start! )

I have another car (same make/year) that the Security Light flashes ALL the time (even with the key off) and it starts ok, but the light runs the battery down.

Help!!  :-) Thanks.


Answer
The first car has a problem with either the:

ignition key.
ignition key cylinder lock.
wiring from ignition key lock to pass-key module.
pass-key module.


The second car has one of the above faults. If you want to aquire numerous pictures and directives on how to diagnose and fix these problems, You need to e-mail: cadillactech@hush.ai