Q&A

 Journeyman

There are three ways to disarm the alarm for this vehicle. 1 & 2 are using the key to manually unlock the front doors. If you unlock the driver's door, then open it and the alarm goes off walk to the passenger door and unlock it with the key. Now, if the alarm shuts off you have a bad switch or the wiring to the switch is bad in the driver's door. 3 is to use the anti-theft code to unlock the doors and see if the alarm goes off. First you want to lock all the doors, then use the code to unlock the driver's door, open it and see if the anti-theft goes off, if it does not we know that part of the system works. If you could not turn the anti-theft off with either key, but could with the code, then you have an issue with the disarm circuit to the lighting control module. Both switches at each front door lock cylinder are wired to the same circuit. Make sure that the trunk key cylinder has not been tampered with or the hood switch is in the closed position. Try these steps first and let us know what the results were.

1990 ANTI THEFT HOW DO I DISABLE THE SYSTEM BUICK RIVERA