usually the door isn't completely shut if the light is still on
A door switch is broken or out of adjustment.
the seat belt sometimes makes the light stay on
The door being open.
To identify which door is causing the "door ajar" light to stay on, first, visually inspect each door to ensure they are fully closed. Next, open and close each door one at a time while observing the dashboard light. If the light turns off after closing a specific door, that door is likely the culprit. Additionally, check the door switches for any signs of damage or malfunction, as faulty switches can also trigger the warning light.
Either the manual light switch is on or the door switch is damaged.
try to close it then never use it ...if i could keep it closed i wont open it again i think it has something to do with the mechanics in the door itself
To the right of the headlight switch is a gauge light dimmer wheel , if that has been rotated all the way up , your courtesy lights will stay on with the doors closed. If you also have a door ajar light lit up in your gauge cluster , then you may have a sticking door ajar switch , or something isn't closed properly
The interior light on a 2003 Astra may stay on due to a faulty door switch, which detects whether a door is open or closed. It could also be caused by a malfunctioning dimmer switch or a problem with the vehicle's electrical system. Additionally, if the light is set to stay on manually, it will not turn off until the setting is changed. Checking these components can help diagnose the issue.
the switch to that perticalar door is not making contact when the door is closed, Does the dome light go off or stay on for the same door ? check the switch actuator ,it maybe bent where it does not touch the door when closed.
The back hatch may be ajar.
That is actually a door switch problem instead of an alarm problem. Find the door that is not registering as closed and check out the little switch by the hinges, you might just need to spray it with some WD40.
The Ford Thunderbird door should trigger the lights to go off. The sensor associated with the closed-door may need to be replaced.