Land Rover Repair: Alarm system in 2000 Discov, white lithium grease, land rover discovery

Question
I have a 2000 Land Rover Discovery.  I had some work done on it awhile ago for the brakes and since then my alarm system has randomly been going off.  Some days when I push the button to lock my car and set the alarm it's just fine.  Then randomly on other days it will go off like 30 minutes to an hour later.  It doesn't stop until I go down there and unlock the driver's door.  I don't know what to do because I can't lock the driver's side door without using my alarm system.  I tried taking out the noise part but my lights would still show my alarm system going off.  I don't know if this is related but my interior light in the back sometimes wont go off until like 5 minutes after I have started my car.  What can I do about this?  The repair said it would cost anywhere from 300-1000 dollars

Answer
Hi Denise,

check each of the door sensors to make sure they are working properly.  Where I live, fine particles of dirt and salt seem to work their way into that area and the door sensors sometimes stick.

Usually, when you press on the sensor button (black) you can feel the spring behind it.  If it gets dirty, this button can jam and the spring can even corrode.  I have sprayed white lithium grease around the door sensor and it seems to lubricate well.  

This might be part of the problem.  The other part of the problem could be that the alarm ECU is slowly starting to fail.  I wish I knew how to prevent this from happening but I don't.  I also do not have a means of by-passing the alarm.

The next time you have trouble, check all the door sensors.  Give them a quick push to see if it helps.

Best of luck,

JohnMc