1995 sl500 cannot set alarm on driver side but some times it works and sometims it dosnot

You need a mobile auto electrician with a pro grade scan tool computer.

Google ... 2 seconds and this;
https://auto.needmanual.com/1998-mercedes-benz-sl500-sl600-r129-owners-manual.html

that truck dont came whit factory alarm you have an aftermarket alarm unde the dash on the driver side you goint to find a small switch is the valet switch press the switch and turn ignition switch to on position that discobnect the alarm

Pull the alarm fuse in fuse panel or under the hood

You can try the passenger side of the door to enable it, and disable it, that all you can do. Or if you know someone who know how to disable the alarm an auto electrician are the only one who know how, the only thing i will do is speak it and not give details first they cut the door alarm. they dont have too but sometimes autodoor lock get in the way. they jump the starter relay permanetly and its done I do this for customer left and right It faster and cheaper alarm are headache and the market to remove is big yours is easy its OBD1 . find a person who know his skill.

Try locking and unlocking the drivers door using the key. Usually that will re-set the security system. Also try the rear hatch lock as sometimes that is used instead of driver door.

can u shack it a little bit then it comes on it is the connector bad if not the ground could b lose

be careful about that. there is a lot involved concern these alarms today. try just turning it off locate your fuse box or a small access panel around the steering column. youll find a button. push it sometimes the alarm needs to be sounding off.

try locking and unlocking the drivers door with the key. that will some times reset an anti theft system.

hope this helps.

Mike

When I accidently set of the alarm on my 97 Jetta, I had to lock and then unlock the drivers side door(passenger side works too). This shuts off the alarm.