I have a sc400 and if I unlock the door on the drivers side the alarm goes off. If I unlock the passenger side nothing happens. Any suggestions?

 

mine dont do that but but jw is there a chip in our keys cuz i dont have a remote,and if it does go off how do we stop it?

 

It sounds like the security harness running to the driver side door key cylinder either came unplugged or is not recognizing the key turning the cylinder, i would remove the door panel and check the wire and plug thats attached to your inner door handle, if it fell off or something theres your problem,
another possible culprit could be your driver side door harness that connects the door to the car, often in our sc's over the years the repetitive open/close of the door and the brittle wire insulation cause shorts inside of that wire boot, ive had similar issues with windows and locks randomly working when the door would be partially opened and vise versa.. GL

No chip in the early sc's the way the factory alarm is disarmed is by unlocking the car with the key when theres no remote present..

 

Alright Ill take a look at the harness in the door thx.