I have a 2001 Elantra. One day upon inserting the ignition key, an alarm
(like the one when a door is ajar)came on. The car was not started yet.
Even when starting the ringing never stops. Door panel light stays on
continuously even when car is off. The only way to get the ringing to
stop is to turn on the rear defogger (found this out by accident). Does
anyone know how to fix this problem??? Laney

 

First, check your fuses. The rear defogger thing is definitely bizarre.

If they're ok, check the driver's door switch -- the plunger thingy under
the black rubber cover on the b-pillar. It may be broken.