Factory MB alarm
 

:confused: I recently puchased a 1985 380se and everything is still going fine with the attempt to revive this neglected beauty. Thanks to all who have posted questions and answers in this forum. The car (121k mi.) runs great and looks good now, however something is just bugging me now. Does my car have an alarm system? I tried the door test as posted, but it didn't work. The door latch won't release the door nor will the button come up if I lock the car with the key. The vacuum system seems to be fine as all four doors and trunk lock and unlock properly when I use the key. I only have one key (square black w/ hole).
So I assumed no alarm or disconnected alarm. Then today I unlocked the car from the passenger side, opened the rear passenger door and then my headlights and taillights began to flash. They continued to flash untill I locked and unlocked the car from the drivers door. Can anyone tell me if :
1. I have an alarm
2. If it is functional
3. Where is the module

location of module
 

Yeah on my 1987 300e the module was located behind a panel on the passenger side foot rest.

Pull back the carpet on the front pass side and there should be a "faux" plastic firewall. Behind that you should might find the control unit. I know this is the case for the later model W126s.

Also, there is a rubber access piece that can be taken out near the driver's door latch to let you get at the wires which attach to the door handle/lock. Sometimes those can be loose or disconnected.

After further trial and error, I really do have an alarm system that works. It seems to only work if I activate it by turning my trunk lock to the right and pulling out. It does not work by using the key in either door. Am I doing something wrong or is it faulty. HELP!:(

All Mercedes-Benz alarms would arm automatically once the car is locked, either at the driver's door or trunk (on W123/6) or both front doors and trunk (W124/140).

M.B. alarms also have a check/warning light which is red and should flash intermitently when the system is armed. It is usually located at the center dash with the row of switches for the rear defrost and rear dome light.

Check if the light flashes when you lock the car from the driver's door.

A. Rosich
S320, 1998
E320T, 1995

I belive the alarm indicator should be in the central locking switch itself. Look in the owner's manual to be sure.

Older Benz models (like W123/6 and even the latest facelifted W124s) do not have central locking switches in the center dash. They had to be locke with the door lock (unlike newer models like the C/E/S classes).

The alarm equipped models just had a black rectangular fixed cap with a very small red L.E.D. in the center (the size of a switch).

A. Rosich
S320, 1998
E320T, 1995

126 alarm
 

If you're lights are flashing but no sound then I would guess you're alarm is working,but the Horn/siren is disconnected.
My alarm on my '85 380se would go off in the middle of the night every once in a while,even though I never used the red dotted Key?.Yesterday,I finally disconnected the closest connector to the floor behind the passenger foot rest panel.Everything seems fine now.I dont need an alarm anyway.



'85 300se
'81 240d
(girlfriends '82 300TD Turbo)

I lifted that plastic firewall under the passenger foot rest and found this box ( 126-820-08-26). Is this the alarm module? Also there was this 4 point wired plug, but nothing was plugged into it. What is it for? BTW, what a difference a new set of Beru wires made! :)