How to disable alarm on 86 420SEL - PeachParts Mercedes-Benz Forum

svmercedes · #1 08-19-2003, 01:33 AM

So, my alarm has been going off like mad at 5am. Someone said the alarm control module was in the passenger footwell. Well, I see several boxes. I've attached an image. Can someone tell which one to unplug?

Thanks.

sixto · #2 08-19-2003, 03:00 AM

Black box on the left. You can pull off both connectors but in my case pulling just the one closer to the firewall disabled the alarm with no adverse effect.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

svmercedes · #3 08-19-2003, 12:35 PM

Hmm...I wonder what the other plug is for. Any ideas?

sixto · #4 08-19-2003, 10:04 PM

Maybe the other plug is just for trigger switches.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

Thomaspin · #5 08-21-2003, 05:16 PM

I found if you just pulled one you could hear a clicking noise (like a relay) with the engine on, so I pulled both. Car works fine, and no one is about to steal a 12 year old 560SEL (I hope).

h_shek · #6 08-22-2003, 02:54 AM

hi there:

Just wondering does the control module reads "BECKER" on it?

I think the W140's are located at the boot next to the fuse box. I am wondering if we can do the same by unpluging the thing to get the car start.

My concern is that if I lost my remote, I can use the metal key to get in the car with the "horn" going off. I however need to bypass the fuel cut-off and START the car.... Do you think unpluging the thing will allow me to START just like no alarm is installed??

sixto · #7 08-22-2003, 03:05 AM

You should start a new thread to catch the interest of folks who really know the W140. The W126 factory alarm is much simpler than the W140 factory security system. The W126 alarm is just that - it doesn't disable anything, just makes noise and flashes lights. It won't hinder anyone's attempts to start the engine and drive away.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

420seltim · #8 03-30-2006, 09:16 PM

all i gotta say is thank god i found this post.
i got off work today and the alarm magically decided to arm itself (even though i dont have a master key) and go off. i eventually found the horn and took that out and found out if you turn on the headlights nobody will see the flashing (good way to aviod cops) i was about to go spend $50 at the mbz dealer to get a new master key but i found this post and id rather just disable the alarm all together. besides, who wants a 20 year old 420sel anyway.