Just replaced the bulbs in the vents and now all the lights on the dash, center console, etc. of my '88 300E are working. Just wondering if the light switch has any illumination. It would seem logical that the symbols above the switch would light up. Anybody know if there is a bulb behind the switch?

As far as I know the switch does not have any lights.

Yes
 

The symbols above my light switch are lighted (1990 300E) when the lights are on.

Hi Crowe,

I am figuring that out myself too. I know that the W124 series cars have lights on the switches but not the W123's.

There is a tiny light bulb inside the knob, open the orange button right on the knob and you'll see it. Changed mine, but it still does not work. Any help out there??

The symbols light on my 87 300E as well, so if a '90 lights, and an '87 lights, then maybe yours should as well.

I have never done this procedure, but an article in the Star magazine on installing Euro lights talked about removing that panel to install vac hoses and a Euro panel for a headlight level control, so I bet that is how you get to the bulb(s). The article says "...pull the headlight knob off it's shaft, and undo the 24 mm nut holding the panel; wiggle out the panel, left side first." So, if your brave, and trust the Star article, it looks like you have access to the bulbs (in theory). Let us know if this works - it is logical, but the path to ruin is paved in logic!

I think the only bulb that is in there is for the orage dot, which lights up when your rear fog light is on.

Orange Light
 

The light under the orange button is for the aft fog light which is available in some countries (not in US).

If you notice, your light switch has *two* detents as you pull out the knob when turning on your fog lights...actually the first detent turns on the front fog lights, and the second detent turns on the aft fog light (in those countries that it is available).

If you look at your tail light assemblies, you will notice that (in the US) there is one *blank* light position on each of the tail assemblies. Well, that position will contain (in non-US delivered versions) a rear fog light on the drivers side only..left for LHD, right for RHD cars. It is an extra bright bulb to help people from running into you from the rear in dense fog.

The orange button light will illuminate, if you have the aft fog light on.

Sorry, I thought Crowe was asking if the symbols above the light switch should light - mine do - so I gave him directions on removing the panel. Am I confused - does he want to make the (unused in the US for some models and years) fog light button light up?

I think Crowe was asking about the symbols above the light switch. Benzie was asking about the orange dot.

more info...
 

Just to let you know:

The symbols around the light switch of the W123 are NOT illuminated.
The symbols around the switch of the W124 ARE illuminated (or, at least, should be).

Pull off the knob of the light switch (and then you will see the fog-light indicator) and untighten the nut of the light switch. Pull the black panel (gently) towards the driver seat and after the opening passes the threaded part of the light switch, move the panel to the left (door-side) to unhook two (or three) clips at the back of the panel between switch and steering column.
The bulb is stuck in a plug at the back of the panel!

greetingz,

Thanks everyone!
 

I was asking about the symbols above the switch. I will check it out.

Correct bulb
 

Before removing the cover at the light switch I need to purchase a bulb. I expect that the correct bulb is the same small 0.4 watt bulb used in the air vents. Is that correct?

JEP, correct
 

The bulb in the back of the light switch panel is the same as in the air vents.

greetingz,

The Rear fog light I believe was available on US versions. My car has it, and is a US version not a euro version.

Its basically a really really bright rear brake light when on, its basically brighter than the brake lights themselves.

Alon