Central Locking/Alarm

[slor911]

My remote no longer activates/deactives the central locking system nor alarm in my '90 500 SL. I push the button, nothing happens - no flashing red or green light in the door handle. The same is true when I use the key itself in the door lock (either with the smart key or valet key) .. only that one door is locked/unlocked, so I have do walk to both doors to manually lock each, then lock the trunk.

If that wasn't bad enough, sometimes when I unlock the drivers door and start the engine, the alarm will go off while the car is running.

It's been and is a great car ... it just seems a little confused right now.

Any ideas, thoughts, or suggestions on what the cause is? or better still what the cure is?

Any help greatly appreciated.

Thanks!