Starting problem

I have a 1992 Buick Riviera, car ran all day and then that night it would not start, all I hear is a click under the dash in the start position. I have checked the battery, replaced the ignition switch (the switch not the tumbler) checked all the fuses, and the fusible link at the starter, I get no power to that link on either side, I can jump the selinod and start the car, but only for a few seconds then it stops. I read some articles on passkey (alarm systems) and it seems to be exactly what my problem is, but how do I check that or bypass it to find out?