Electrical: Must dash come out to change light?

[Leicamshooter]

My dashboard won't ligth up at night. I suspect there is a control knob to turn it on, but I've fiddled with all of them and can't get it to light. I'm sure the bulb (bulbs) is blown, and I'm wondering how to exchange it? Do I have to pull the dash out to get access to the bulb?

Thank you,
G Medina

Further: (1.5 hours later) I've nudged the dash loose, but it looks to be connected with cords inside (obviously). I assume these are the speedometer, gas etc, so I'm afraid to pull the dash all the way our for fear of disconecting something important.

Again,
thanks!

[Sokoloff]

Dash doesn't have to come out, but the instrument cluster does. Maybe that's what you meant. It should be connected by the oil pressure line at the back of the gauge, the electrical cord, the speedometer cable and the line to the cooling temperature sensor. On some cars, the whole temperature sensor line has to be pulled out, Not sure about your car. Here is a description of the job on a car about fifteen years older than yours - http://www.mbzponton.org/valueadded/maintenance/cluster.htm

Len

[MBman]

If you sure it is not a fuse ....
Just did this on my 71 220, Put rag over steering shaft to avoid scratches
Gently nudge dash out, remove electrical connection, this can be quite tight so be careful, unscrew speedo cable, and oil sender
You should be able to pull dash pod out fully now, do not remove or attempt to remove temp sender. Unless all your bulbs are blown, it probably is your reostat. They get cruddy with age
At the bottom are two screws that attach your light reostat to the panel. Unscrew and remove reostat. I took mine apart and cleaned all surfaces with 600 grit paper and contact solution, put her back together and back on dash and lights now dim and brighten.
Good time to check all the bulbs and clean them. They all come out of dash with a twist of the black holder.
I have an extra old reostat if yours is trashed, they are over $75 new!

[wpg300d]

My 76 has problems too. I have discovered that if I turn the rheostat to just the right spot, I get lights. I plan to fix it in due course but don't think I will replace the original rheostat. The dash lights are not really all that bright in any event so I figure that I will just bypass the rheostat and essentially keep them on full bright.

[pch2021]

change your rheostat...full birght means that your bulbs will burtn out faster, and that you MYA melt your cluster. Just go gt another rheostat....

[Odrec]

There was a small article on a similar forum on how to change your cluster light for a couple of LED's. I did it on my W124 but my W115 is stock. It does give better lighting.

[W.L.SOON]

Hi guys! Please excuse me for bringing up an 'older' topic,but may I ask what is the actual/recommended wattage rating for our W115s instrument panel bulbs.

I took mine out for cleaning the other day,and noticed that most of them are 5-watts,(the few others couldn't be read.)I also noticed that my rheostat has been bridged/bypassed,thus rendering it useless(the contacts seems loose,oxidized and dodgy).Perhaps I should take it apart and service it?

And what do you say about replacing the bulbs with white LEDs? Seems like a neat idea to me!But then again,I like the yellowish glow of our bulbs at night.

Well,thanks guys!BYE for now and GOD BLESS!!! :) :) :)

[W.L.SOON]

Hi guys! Well,I've searched the forums and found quite some comments on the bulbs and LEDs issue.So,I guess I've got my answer.

I've cleaned up my instrument cluster:the gauges,the glass dish and bulbs,and now,it lights up very bright(for a W115,that is! :) )at night.Perhaps I'll just try to fix up the old rheostat so that I might be able to control the brightness of the 5-watt bulbs(less brightness,less heat on the holders,yes?).Then again,I seldom drive at night and if I do,it's only for short distances.

Well,I'll see as I go along.Thanks to all.BYE for now and GOD BLESS!!! :) :) :)

[MBman]

I was able to fix the reostat on mine. I carefully seperated the halfs, keep close watch on the little springs!, cleaned all surfaces, final shot of contact cleaner and it works great. Without it you run agreater chance of burning out your bulbs prematurely. good luck

[OU1954]

I'm sure this has been covered in other postings but a search fails to find them.

I have a burned-out light in my instrument cluster and one that is flaky.

There are apparenetly 4 lights in that group but I understand that to get to them you have to drop the steering wheel, using a special tool, etc.

Can someone either comment on this or send me a private message as to where to find an appropriate posting?

DAW :)


98 SL500
99 ML320

(Waiting MBCA membership packet)

[W.L.SOON]

Hi! A 98' SL500,eh? Fix one? I've yet to see one here in my hometown!
BUT IF it's really necessary to remove the steering wheel,it's gonna need some careful attention;you know,the air-bag,the clock-spring,the 'keep-the-steering-straight-and lock-it' rule and stuff!

Hope you get what you're looking for! Sorry that I'm not able to help out here.
Well,all the best,BYE for now and GOD BLESS!!! :) :) :)

[OU1954]

Well, so far I'm about half way there.

I have the Star Classic Service Manual Library DVD for Model 129 and it does have a section on Instument Cluster Removal, and also on removal of the 4 panel lights, one of which is burned out on my car.

I now have the two tools, "official, MB tools that is", which are simply two 1/16 wires with handles on one end and short hooks bent on the other end. (When you read further down you will understand why just making wires with hooks on the ends is not a good idea, the force required must be considerable.)

The instructions say to insert the hook ends, with the hooks pointed down, and when the wires are all the way in, to rotate them 90 degrees so the hooks point towards the cluster assembly. Then pull back til the hooks engage, and then pull the cluster out.

This almost works, and I can actually feel the hooks going into some sort of slot associated with the back of the assembly, but when I pull, with what I think is reasonable force, the assembly doesn't come out. The ends move a bit but the bottom center doesn't.

I then ran a thin polyethelyne body putty knife around the entire perimiter of the assembly because it seemed that it was slightly stuck in some places. I also lifted the soft part of the dash panel along the top edge of the cluster to be sure it wasn't holding anything.

I then repeated the pulling process, but there is some sort of hang-up, mostly in the bottom center.

No idea how much force to apply or what will break first, the tools, the cluster, or me.

I have had similar things happen to my wife's ML320 when removing the center console (the wood part) so I could repair the window switches. It took several attempts over several days, with a little help from the wedges before the panel came up. Each time the panel moved a little more, and each time I had the guts to push harder and use more force on the wedges.

I wonder whether I'm facing the same thing here.

Anyhow, if anyone has ever done this, just how much force should I expect to use?

Thanks,

DAW :confused:

[dcashour]

I too am in the midst of cleaning up the instrument cluster. I just got new (used) bulb holders from mbman, and a clock on ebay (doesn't work yet). All of the bulbs in my cluster are 3 watt, not the 5w some of you mentioned. Does anyone know what the correct wattage should be? The few bulbs that currently work seem to be bright enough for night driving. I need to clean the rheostat as well. Where can I find the contact cleaner?

Thanks.

[OU1954]

I too am in the midst of cleaning up the instrument cluster. I just got new (used) bulb holders from mbman, and a clock on ebay (doesn't work yet). All of the bulbs in my cluster are 3 watt, not the 5w some of you mentioned. Does anyone know what the correct wattage should be? The few bulbs that currently work seem to be bright enough for night driving. I need to clean the rheostat as well. Where can I find the contact cleaner?

Thanks.

You can buy contact cleaner at any legitimate electronics store, that is one that deals in electronics, not just computers or TV's.

Actually, contact cleaner, as we know it, is just a solvent and is designed to remove grease. Some versions may remove some surface corrosion but I think those days are over.

Since you will probably be lightly buffing the surface of the rheostat (if you take it apart) and want to finish it off, use some ordinary rubbing alcohol and then wipe it dry.

If you want to spray something into the unit without taking it apart, then you will have to get some contact cleaner. If you are very careful, you can squirt a little liquid wrench into a wire-wound rheostat and clean it that way.

DAW

[mgburg]

WHOA!!!! :eek: :eek: :eek:

Watch what yur' sprayin' thar' partner!

Some contact cleaner sprays will EAT/DAMAGE certain plastics! If you have a small, discrete area where you can test the spray, I'd HIGHLY RECOMMEND you try a little squirt there. DON'T TRY IT ON YOUR ONLY PART OR OVER-SPRAY THE CLEANER ON THE INSTRUMENT CLUSTER LENSE! The spray will eat/mar the plastic and unless you have a replacement part, you'll be left with a "trashed" component/instrument cluster. And, if the damage is bad enough, nothing will work correctly.

"Forewarned is being forearmed!" :rolleyes: