Car Alarms: 1998 grand marquise, valet mode, dash area

Question
factory car alarm goes off for no reason honking and lights  everything till I turn it off by the key switch

Answer
It's an after market system
from your description.

To simply disarm it, locate and use the
valet/overide switch.

To start, look under the dash area for a button or,
a toggle switch. When you locate it, turn on the
ignition key, press and hold in the button (little
spring loaded micro button, red or black possibly)
until the alarm chirps 1 time. This should over ride
the system, and only the keyless entry part,
if installed, would still be operating.
The LED (light emiting diode) light in the dash
should also go on solid.=VALET/OVERIDE

This stops the alarm except for the keyless
entry if installed. The next step is to
either remove the alarm or, try to identify,
and get new remotes for it.

But once in Valet mode, it will allow the car
to start and operate like there was no
alarm at all. Repeat steps to put into user
mode.

Let me know how it goes.

ALARMTEK
CARALARMMAN.COM