burned out instrument cluster light - PeachParts Mercedes-Benz Forum

Imatation · #1 03-30-2003, 09:06 PM

I have an interesting problem, the illumination light in the instrument cluster in my '89 300E seems to be 1/2 burned out. I know that is not possible, but its putting out nearly no light at all. This is a completly sudden change, its not like it gradually got worse I think it could be some sort of short drawing all the current, but this is the only light that is affected, and nothing else in the car has really changed. Does any one know what could be the problem, and also how would i go about removing the instrument panel? Any help or ideas are appreciated.

Ali Al-Chalabi · #2 03-30-2003, 09:51 PM

There is more than one bulb back there. At least one of them is probably burned and needs to be replaced.

sunil190e-1.8 · #3 03-31-2003, 06:19 AM

have you checked the rheostat which is like a dimmer switch for the insstrument cluster-if you turn this clockwise/counterclockwise,then the cluster should iluminate or dim depending on the position of the knob-it is located on the instrumewnt cluster similr to the one for adjusting the clock

#4 03-31-2003, 06:38 AM

You might like to check out:

http://instrument.articles.mbz.org/renew/

Sounds a bit involved to me, but if you are handy with a soldering iron, it looks like it could be fun

G-Benz · #5 03-31-2003, 10:37 AM

I agree with sunil190e-1.8 on the dimmer issue. I've kicked myself on this one a couple of times...

Th age of your car though would imply that your bulb(s) are about due for replacement anyway. If you have to go through the trouble to pull the cluster to replace one, go ahead and replace them all.

Gilly · #6 03-31-2003, 11:07 AM

There are 2 "illumination" bulbs. If 1/2 your cluster is dim, it would suggest that one of them is inoperative. They are located approximately in the area of the turn signal indicators and feed light into clear plastic light diffusers, which spread the light out on that half of the cluster.
If neither of the bulbs seem to be working, i would agree that the dimmer is often the problem.
If the cluster lighting seems to be too dim (but operating) on BOTH sides of the cluster, are you sure the dimmer switch is turned up to full brightness? I've had this problem presented to me a number of times where the dimmer was simply turned down too far (accidentally I suppose) and the owner didn't know that the dimmer switch was even a control that they could use!

Gilly

MTI · #7 03-31-2003, 03:07 PM

If you do pull the cluster to change the two wedge bulbs that illuminate the cluster, go whole hog and change out all those little 2w indicators. As we get older, it wouldn't hurt to upgrade the wedge bulbs to either the Raybrig or PIAA hyper whites, to make it easier to read.

Imatation · #8 04-01-2003, 05:47 PM

ok, so i just took out my instrument cluster and, none of the bulbs are burned out. I even checked them with the multi tester. They dont even have the black haze they get when they get old. I know its not the dimmer because my car doesnt have an illumination dimmer, so i am back to square one, with no idea whats wrong. any more help is appreciated.

MTI · #9 04-01-2003, 06:47 PM

Doesn't have a dimmer? Hmmm . . . are you sure? On the 190E, MB incorporated the dash dimmer switch with the trip odometer control button under the speedo. I don't know about your model, but there's a lot of 190E owners that are surprised when the find they have a dimmer switch.

Richard Eldridge · #10 04-01-2003, 07:53 PM

My 85 30E has a dimmer, and so does my 90 300D. There are two knobs protruding from your instrument cluster. The one on the right sets the clock and the one on the left resets the odometer to zero when you push it in. That same knob controls the potentiometor that sets the dash illumination for the dash. Turn it ALL THE WAY to the right. It may act like it doesn't want to turn, but turn it left, then right , and it will almost certainly brighten your lights.

Gilly · #11 04-01-2003, 08:33 PM

Yup, sounds like a classic case of the dimmer switch getting inadvertently turned down. As has been outlined, it DOES have a dimmer, you just don't know it. You're not the first to not know this.

Gilly

Imatation · #12 04-01-2003, 09:02 PM

Yea, i feel retarted, there is a dimmer switch. But.... I have an excuse, its stealthly hidden on the odometer post and i literally had no clue. Thanks for all the help, my instrument cluster would still be in the dark with out you guys.

G-Benz · #13 04-02-2003, 09:47 AM

As said before...we ALL got burned on that one at least once!

It's up there with "taking apart appliances before realizing that it isn't plugged in"!

But if that cluster is out, go ahead and replace those bulbs! Otherwise, you will be staring at the back of the cluster again in a year or less!

Richard Eldridge · #14 04-02-2003, 10:24 AM

I don't think bulbs "wear out" as parts do that are subject to friction.

Annoyed by the somewhat high prices of fuses and bulbs (and even more by the nasty habit of the chain stores bubble-packing these things two or three to a card) I began harvesting such things from u-pick junkyards, where some believe that small stuff that will fit in your pockets is, well "free". This is the attitude of the tattoed ex-cons that clerk at the U-Picks I frequent. They don't charge for small stuff, because they assume people will just stuff it in their pockets, which I thing most u-pickers do. When I put bulbs and fuses on the counters, they snort in a scoffing way, as they might at an altarboy who returns Fatjher Flannigan's unused mustard packets to the Ho Jo.

Fuses that are corroded and bulbs that have that black haze on them I don't use, but I have found that a junkyard bulb often needs replacing no more often than one bought brand new.

Many Benz bulbs are quite hard to find as well, and if one can find a nr. 2207 DRG Fischer 12v/4/mHC bulb such as fits in the automatic transmission shifter of a 123-300D, at the U-Pick, one should take it, because that bulb is only available in the most esoteric of specialized lightbulb shops. It is ecologically sound to do so, as a six-mile trip to purchase a $1.50 bulb uses almost as much in fuel as it costs.

I suspect that what makes a bulb fail is not that excessive use has taken away all its electrons, but that it was manufactured with a teensy amount of air in it, and that air corroded the filament. If the bulbmaking apparatus pulled an absolute vacuum, then I assume that the bulb would last eternally. Many of the bulbs in my 1977 Celica lasted through the 160,000 miles and 26 years of its life. A bulbmaking machine that made perfect bulbs would, I fear, go unrecognized.

It is a good idea to get some dielectric or "bulb" grease to put on your bulbs, as this keeps them from soldering themselves inside a socket and requiring a surgical (or needle-nose) extraction.

So I would say that bulbs are like the lottery: someone has to win the lottery, but probably not you and probably not today. At some time your left turn signal will go pffft but probably not that bulb and probably not today. If you have a supply of cheapo bulbs on that rainy Sunday in Yeehaw Junction, it will bring a warm feeling to you: trust me.

By the way, access to the auto transmission light is easy: just remove the ashtray, remove the two screws and the bracket under it and lift up on the wood trim: removal of the entire fool console is not necessary, as the Haynes DIY seems to suggest.

Imatation · #15 04-02-2003, 04:32 PM

What bulbs fit in those sockets? I noticed that there were two types of bulbs used for everything. If i do replace the bulbs i would have to pay the extra cost and get after market bulbs or a better quality than whats in there. So, does anyone know if piaa or hella or a company like that makes replacement bulbs, and what are the item numbers for the bulbs. Thanks.