Mercedes 124 Anti Theft system

I have a 1990 300E with over 200000 miles on it. When I bought it from the 2nd owner he advised me that the Anti theft alarm had started going off randomly and that he had disconnected the horn but that the headlights would continue to flash. He instructed me to simply use the truck lock to turn off the flashing. That works but I would really like some input on how to dissable the alarm permanently. All help appreciated. Thanks-Ken

Forums

Body and Interior Specific Aid

Chassis Model Number

W124

Unplug the brain

Hi Ken, You are not alone in this one. This is happening to 7 out of 10 of these older 201 and 124 chassis cars. It can drive you nuts and can be very embarrassing. In one of my cars the alarm went off when I opened the car's door and nothing I did could get it to stop. I had to quickly drive away to a remote area and unhook the ground to the battery cable. I then disconnected the alarm permanently. Good thing I had some tools with me. It has proven to be a system not be worth trying to fix it. Who wants to steal these older cars anyway!

Best solution is to just un-plug the alarm brain. It is located under the passenger front foot well. Remove the floor carpet and then remove the black plastic cover up next to the firewall. There may be a couple components under that panel so you will want to unplug the right one. I don't have the number or a picture handy but it is the smaller black unit off to the right that is mounted long-wise vertically. Pry out the multi-pin plug(s) with a small flat blade screwdriver. This will completely disable ALL alarm functions.Â Kent Bergsma

Security system

Pulled the carpet, didn't see a black plastic cover other than the heat ducting in front of the seat. Nothing in the firewall area appeared to be accessable. No black plastic covers. Are there any variations such as a later production model ... Helllp! Thanks-Ken

No advice, just a funny story about my alarm system failure.

Several years ago I was driving from Roseburg OR to Redwood City CA. I often like to travel in the early AM to avoid traffic. I pulled into Medford about 2:30 AM to fuel up, and after paying the attendant through my open window,I went to close it up and heard a noise like a rifle shot and discovered that the regulator had broken with the window wide open and the outside temp in the high 30's. I pulled a hat low over my head and wrapped up in a sweater with a leather jacket on over it and still nearly froze to death going over the mountain passes.South of Mt. Shasta,I pulled into a rest area to warm up a bit, and when I went to leave, the alarm system started sounding off, horn blaring and lights flashing for about a minute every time I applied the brake. I made it the rest of the way home and only set it off a couple of times. when I approached the Dumbarton Bridge Toll booth, I had to brake and the alarms and lights started up again, but the toll taker never batted an eye,I guess nothing came as a surprise to him. anyway after I got home I figured out how ti disconnect the brain under the mat.I thought I was going to freeze to death, my face was frozen in a grim rictus for what seemed like hours.