I dont know what this means, or how it came about, but in my '93 S500, in the interior on the door lock button, there is a red light that stays on, what is it, and it wasn't there awhile back. I dont know if anyone in my family did anything, and they are all too scared to 'fess up anyways.. So what does it mean, and how do I get it off the little button?

Ill try and find a pic.

edit - Found a pic and edited it :

 

Hmm, strange. The 600SEL's door lock button is located on the drivers side door and it doesn't have a red dot for a light.

 

Huh? Mine is a S500, and the red light isnt used to illuminate the button at night, its just a red light thats steady all the time...

 

Yes i know you have an S500. Just saying the 600SEL's door lock button is located in a different place etc...
I have no idea why it's doing that? The locks work perfectly fine right?

 

I have a 93, 600 that has the exact same switch, it flashes red when the doors are locked from outside indicating the Alarm is on. Plus it stays illuminated when driving with the doors locked. it sounds like it's stuck thinking the doors are locked, or possibly it is now working properly and had a bad connection or something. One thing puzzles me in your photo, we both have 93s but your radio looks completely different from mine?

 

I checked my 96 S600 this morning. The red light is there but off. When the doors are locked while in the car it is still off. I do not recall ever seeing it on. The only thing I did not check is to see if it is on when the car is turned off and locked with the security system on.

 

Yeah, the radio is completly different from the 600. When you park the car and lock it, does the light flash every 2 or so seconds?

 

Yep they seem to work perfectly fine.

Well, this problem is just happened recently. Before the there was never a light on there, and I never checked for the red light to blink when i lock the doors from outside. Also, I found the pic off ebay, the interior in the pic is probably from a newer model S-series, I just needed a pic to show a demonstration of what button i was talknig about, my 93 radio is the same as your's, I assume.

I'll check if the red light blinks when I lock the car, havent tried that.

Right now, what I think is, that the system is in some kind of silent mode. Like for example, in cars with aftermarket alarm/security systems, there is also a little button usually put under the dash or steering column for the owner of the car to disable the chirp of the aftermarket siren, and when you disable the chirp, the red LED that normally blinks for various status's of the aftermarket alarm would then become steady and never blinks until the owner re-enables the siren chirp feature.

 

It also could be that your alarm is still working and the bulb/LED, which ever one it is, has gone out.

 

on my (unrelated) button - the boot (trunk) release - the light comes on when the boot is unlocked - maybe the sensor /c microswitch has failed, making the system think that the door is open / unlocked?