Car alarm

I don't see Olds making an Alero for sale in the US in 95 but it sounds like you're having a problem with the security system. Since the vehicle is not in my data base, I can't determine if it's a Passlock or Passkey system. The Passslock system has a relearn procedure that you can try but I don't know if it will help or not.

PASSLOCK 10 MINUTE RELEARN

AUTO LEARN
Time required, approximately 10 minutes:

1. Insure that the battery is fully charged.
2. Use the scan tool in order to clear the DTCs.
3. Turn the ignition switch from the OFF position to the CRANK position attempting to start the vehicle. The vehicle will start and then stall.
4. Leave the ignition switch in the ON position while observing the security indicator.
5. When the security indicator turns off, which can take up to 10 minutes, turn the ignition switch off. Wait 10 seconds.
6. The BCM and the PCM will learn the new code on the next start attempt.

Also, just a note. Disarming is not an option. Either system is integrated right into the operating system and has to be operational for the car to run.