midnightsaint

What this little led does. It never lights up. And I have no keyless entry.

190E 16V

Looks like an LED to say MB central locking with alarm engaged

midnightsaint

So I can't find a central locking button. Like in the later modles.

190E 16V

It is only activated by the trunk and door keys. The locks alone can be closed from inside by pushing down the knobs on the top of the door panel.

Greger-meister

It looks to me like the previous owner added an aftermarket security system (and then removed it, because you said you don't have keyless entry.) I had that on a pre owned BMW, it had remote start, alarm, keyless... the works. Whom ever installed it, drilled a little hole in an unused plastic cap like that, and put in a little LED.

PaulX608

Mine works. Factory alarm on a '93 400E. Lock the doors with the key to arm the system. May have to look in through the window when it's dark to see it blinking when armed.

190E 16V

+1 above. Looks like a factory alarm LED, on north american W124's from 1993-95. No doorlock/unlock button inside. Alarm/central locking activated by key in doorlocks. Perhaps yours is disabled, or an aftermarket remote was added to activate the factory system.

edcarls

That's what I thought also. Then I remove it and cleaned the red dot from behind. Now I can see it blinking when I lock the door. The red plastic dot is so small that you can barely see it blink. It's best to test it inside a dark garage.

To test if you have an alarm; put your windows down, get out of the car and lock the door with your key, then reach in and open the door using the internal door lever. The horn/alarm would sound off if your car is so equipped. To turn the alarm off you need to put the key to the ignition and turn it on and off.

My 94 is originally equipped with factory alarm without keyless remote entry system. I installed an after market keyless entry system and my factory alarm still works. I'm most certain that your 95 has factory alarm.