Security Problem Horn starts few hours after locking with remote Sometimes trunk will also open at same time. This is 98 Lesabre Limited

Most trunk locks have a holding mechanism at the bottom edge of the trunk lid. Open lid, look at bottom edge. If you see a plate held in with two screws, remove screws, pry plate down to release lock cylinder.

Most likely, you have a vacuum leak if steam is coming from your defrost vent in a 1997 Buick LeSabre. There are approximately 600 million passenger cars worldwide (roughly one car per eleven people). --------------------------------------------------------------------------------------
ZED-Bull

I have a 2012 Azera and had the same trunk lock problem -- there is a security cutout switch located in the top center of the glove box opening which can be tripped if the glove box contents stick up over the lip of the opening. This switch disables the truck release on the dash and on the remote fob. On earlier Azera's the switch is located on the left side of the glovebox opening.

You should be able to go in through the back seat. It will be a chore to remove the seat, but will probably be the only way to get in there. There is a safety release cable in the trunk that will opne it the lid for you once you get inside

Trunk reless relay ! Which year is right ? at the top is shows 1992 Buick . An it also has 2005 ? Which is it ?

IMPREZA: 2005, 2006, 2007 and
FORESTER: 2005, 2006, 2007, 2008
Check for Immobilizer key on Forester XT models only.
information is always subject to change and correction
new remote for 2005 Imprezas.
This is not the same remote as the 05 Legacy/Outback remote which also has truck/gate release on the front and a red panic button on the back.
Lock: press Lock button for 2 seconds or so to lock car, and arm optional security system. The car with chirp once and turn signals flash for locked, 5 short chirps and signal flashes if any door is not fully closed. The dome light goes on for 15 seconds and ignition key ring (if present) will light for 30 seconds when unlocked.
Unlock: press unlock one time for driver's door, press again within 5 seconds to unlock all doors inkling rear gate (wagon). The system does not open the trunk.
Panic mode: press and hold lock button for approx. 3-4 seconds to activate Panic mode. I panic model the horn honks and turn signals flash until either the lock or unlock button is pushed again.
Finder mode: Press lock button 3 times within 5 seconds to activate Vehicle Finder mode. The horn will honk once and the turn signals will flash 3 times
Distance: works within approx. 30 feet depending on battery strength, nearby concrete walls and etc.
Audible Chirp On-Off: the system will chirp when locked or unlocked. To turn OFF the chirps, unlock the door and then push both lock and unlock buttons at the exact same time for 2+ seconds. There will be 2 chirps indicating the the audible is off. To turn the chirp back on, repeat the process and the system will chirp one time when it is back on.
Battery: as the battery ages it will only work as you get closer to the car. When a battery is replaced, the transmitter must be re-synchronized with the Keyless control unit. To synchronize, press the lock or unlock button 6 times.
Programming: 4 codes may be programmed.
Sit in driver's seat and unlock all doors. Open and close the driver's door
Turn the ignition key from LOCK to ON position 10 times within 15 seconds. Be sure to stop at both lock and on. The horn will HONK once to indicate transmitter programming mode is activated. Leave key in LOCK position and don't remove it from ignition.
You now have 45 seconds to complete the programming as below.
Open and close driver's door again.
Push either lock or unlock button on the remote you want to program. The horn will honk 2 times when successful.
To continue and program other remotes at the same time: open and close the driver's door and push lock or unlock on the remote. The driver's door must be opened and closed between each remote you want to program.
Done programming? remove the key from the ignition and the horn will honk 3 times.
DELETE old codes? Reprogram 4 times, it will overwrite old codes.
Alarm Security System: optional on all models. When locked there is one chirp (can be turned off, see above), the turn signals will flash and the red 'security' light will start to flash once every 2 seconds except for STi which flashes twice every 2 seconds.
There will be 5 chirps if a door, hood, and trunk or gate is not fully closed
You can also arm the system by using the power lock button on the driver or passenger door as you get out of the car and then closing the door behind you.
Disarm the system: push unlock for 2 seconds
Lost remote, alarm activated? When you can't use a remote to turn off the system: open the door with a key or try to start the car and the horn will start to honk. Turn the key on-off 3 times within 5 seconds and the alarm will go off and you can start the car. It's simple!
VALET mode: To set valet mode or just to disable the security alarm system: 1. unlock all doors 2. physically open the driver's door 3. hold the UNLOCK button on remote for 2+ seconds. The red 'security' light will then flash 2 times a second until the car is turned on.
System has been Tripped (except for STi): if you unlock the door with the remote and it chirps the signal light flash 4 times, the system has been triggered;
Identification mode: To find out what happened and why the system was triggered:
Open and drivers door, leave it open. Turn ignition key from LOCK to ON 2 times and then leave in LOCK position.
Tripped code: 1 security light flash: a door has been opened, 3 flashes when the impact sensor was triggered, 4 flashes when the ignition was messed with or battery disconnected

do you mean that when you open the trunk sometimes the horn starts going off? Just unplug the wire on the trunk lid on the inside near the lock

Rod

Read your comment on 8/18...Kzactly what I thought. always look at the basics...more times than not, you will find problems there, and , by checking, you eliminate false readings when doing other tests.

sounds like you have a short in the horn wiring or a bad ground wire these grounds are mostly located under the engine compartment near the back wall whitch is called the fire wall or beside the fenders

My '98 LeSabre key also opened trunk. Try it.