124 center console lights went out. :( - PeachParts Mercedes-Benz Forum

Biglex · #1 07-22-2008, 01:56 AM

Anyone know anything about these? I have been reinstalling my fine BE 1432 and now the lights on the gear **** and ac controls are all out. Anyone have a clue? A fuse, bulb, what?

Jeremy5848 · #2 07-22-2008, 02:18 AM

The instrument cluster and center console lights all work from Fuse 3; if only some lights don't work it is not the fuse. My paper book of schematics does not include the climate control and I can't find the lamps in the CD-ROM version, sorry.

Jeremy

Biglex · #3 07-22-2008, 11:44 AM

Yeah it is strange. The dash lights work, but not the lights down on the temp. Then the climate control, windows, gear selection, none of those are on. Also, I am not getting power on the illumination wire to the radio.

BodhiBenz1987 · #4 07-22-2008, 01:22 PM

Are all or some of the switch lights at the top of the cc panel out (i.e., rear dome illumination, headrest drop, air recirc, flashers, antenna switch)?

A lot of these items are grounded to the same place as the stereo, so it's possible you bumped something off-kilter. I have noticed that whenever the shift illumination goes out, though, so to do the rear dome switch, the rear headrest drop switch and heated rear window switch (the 58D circuit).
The cc switches, at least in my 87, are lit by two bulbs shared by all the switches as well as the temp wheel ... they are a pain to change out but not expensive ... if you remove the wood piece you will see them easily. It is unlikely that both would go out at the same time, as well as the shiftgate illumination and the window switches. If it's the same setup as the earlier 124s, then there is a bulb under the shiftgate that is seperate from the window switches. I have had the 58D circuit go out (and come back on shortly thereafter) but have never lost the cc lights and radio ilulmination at the same time. IF I had to guess, I'd say ground. All that stuff is grounded at the "w12" ground, which I'd have to check the exact location of.

BodhiBenz1987 · #5 07-22-2008, 01:34 PM

Just re-checking my wiring diagram ... try checking (or changing) fuse 9 in the fusebox. 8 amp.

compress ignite · #6 07-22-2008, 03:13 PM

So , Did the #9 fuse fix the problem?

Biglex · #7 07-23-2008, 01:55 AM

No luck with fuse #9. I changed it for a brand new one and nothing changed. Even tried a third with still no luck.

Turns out, it seems like most all of the backlighting for the switches are out. The rear headrest switch, the headlight switch. Basically the only ones that are ON is the lighting for the speedo, however the one for the temp gauge is not on.

I checked the groundings, but they all seemed to be quite solid, with no loose wires or any dangling. Any other thoughts? It is pretty dark in there.

Jeremy5848 · #8 07-23-2008, 03:11 AM

Most of the lights work off of N40, the Instrument Illumination Control Unit. The instrument cluster does not. By "temp gauge" you mean the outside temperature or the coolant temperature? [I would prefer that you answer "outside temp," please, as it also works off of N40.]

N40 is behind the instrument cluster. See the picture (from the factory electrical manual) for a rough idea of where it is. The part number according to EPC is 004 545 08 32. I think. The diagram is hard to interpret.

N40 and another unit, N2/4 the Warning Module, both attach to a bracket that is screwed to the firewall. The bracket must be unscrewed and pulled out a little way with both modules in order to get enough room to unscrew the modules themselves. Don't drop the screw that holds the bracket, you'll never find it. I thought I had pics, can't find them.

Jeremy

Biglex · #9 07-23-2008, 03:48 AM

Yes, the temp gauge I am referring to is the outside temp. It seems like everything that is off is controlled by the N40, so I think you may be right. So do I have to take the instrument cluster out? And if so, how much of a task is that?

Jeremy5848 · #10 07-23-2008, 12:20 PM

First, pull back the driver's foorwell carpet and look for the speedo cable near the steering column. It may be held by a metal hook, if so, release it so there is a little slack. If Mercedes updated your model to an electronic speedo then ignore this.

Extend the steering wheel out to its full extent to give yourself more room.

Disconnect the battery. (CYA on my part, for you. I usually don't.)

Make yourself a couple of hooks from a coathanger. Insert one on either side of the cluster (careful to not hurt the dash) and hook the edge of the cluster. Wiggle and slowly pull it out. If it has never been out before it will be tight. There is nothing holding it in but friction; the cluster (my '87 anyway) has four rubber pads (two each top and bottom) for added friction. Sometimes they come off.

Eventually, the cluster will pull out a couple of inches so you can feel behind and unscrew the speedo cable. Let the cable hang loose, nothing will fall out and get lost from it.

Now the cluster can be pulled out another couple of inches. Pull off all of the various connectors. Carefully! You may want to make a diagram and label everything if you've never seen this before. Don't mix up the little light bulbs for the indicators on the bottom right of the cluster (glow plug, etc.).

Once all of the connectors are removed, you can take the cluster out and set it aside. You now have access to the stuff inside.

It's much easier the second time!

Jeremy

Biglex · #11 07-24-2008, 01:04 AM

****!