Factory Alarm problems
 

Hello, I have a 88 supra every time i open the trunk with the key the alarm goes off, the only way to shut it off is by opening driver side door or passenger with the key anybody know what may be cuasing the problem it?, btw this problem started when i removed the battery.

I realize this is an old post and I sure hope you've got this problem worked out. For the sake of making sure this information's available to the next person...

Connected to the back of each lock cylinder there is a small switch. You can disarm the alarm, using the key, via any of these locks. The switch is a mechanical switch and as such they do wear out; The driver's door's switch is typically the first to go followed by the trunk.

I know this is an ancient post, but it may help someone. On the back of the lock cylinder is a plastic cap like Cre is describing. Inside the plastic cap is a sliding quarter-moon shaped copper contact that can become detached from the plastic rivet that moves it when you turn the key. I had the alarm problem on my driver's side door and took the cylinder out to perform the repair. I pushed the quarter-moon shaped clip back onto the rivet and carefully mushroomed the top of the plastic with a small warm blunt rod. Don't go too hot or push too hard or you will melt the plastic too flat and have nothing left to work with. You just want to dome it over a bit to retain the clip. The repair has lasted 25 years as of January 2022.