Horn alarm

[PepperMary]

I have a 1997 ES300, when doors are locked often the horn alarm goes off—but not immediately.  Took to a Lexus dealer where they replaced a rear door actuator for around $400.  Did not fix problem. I cannot find a fuse location for the alarm—if there is one.  Neighbors do not like the middle of the night horn recital!

[Lexus Owners Club]

You should be able to disconnect the alarm siren but the system will still be active and flash the indicators/lights so maybe best to find the root cause of the issue.
I would check all the door, hood and trunk switches to see that they are functioning correctly.

Open each door in turn and see if the interior light illuminates and then goes out after a short period.
If you encounter one that is not doing this then chances are that is the problem.

Also, ensure that your vehicle battery is fully charged as a depleting battery can also cause this issue

[PepperMary]

Thank you for the response to my problem.  I checked all and the opening and closing of doors with the dome light. Light stayed on for all doors, went out evenly at about 30 seconds.      Is there a fuse for the security/alarm circuit?  Not in the fuse panel inside driver side on firewall or outside under hook by battery.

[PepperMary]

Thanks so much Trevor.  Do you know another way to tests the door actuators?  Mechanics seem to want to keep replacing them til the culprit is found--gets expensive.

[Lexus Owners Club]

I would not say it is the actuators as the lights go out when the door is closed so these are working okay.

Check the trunk and hood switches also as these can also trigger the alarm