Instument cluster/console lights - PeachParts Mercedes-Benz Forum

#1 09-24-2003, 09:54 PM

I have a 1980 MB 300D. I have a problem I need some help/advice with please. The problem is that the instrument cluster and console lights ( air conditioning/defrost lights) are not lighting up when I turn on the light switch. I have replaced all the bulbs in the clusters and checked the main fuses . So all of those are good as far as I know.
I would REALLY appreciate ANY help/suggestions as far as where to look now. Cant drive at night without knowing how fast I am going ....
Thank you !!!!

Palangi · #2 09-24-2003, 10:40 PM

On the lower edge of the instrument cluster is the little rheostat knob which controls the brightness. Rotate that back and forth about 200 times, the carefully rotate it slowly until you find the "sweet spot" where the lamps stay on.

A lot of people ultimately just bypass the rheostat by soldering a jumper wire across it.

#3 09-25-2003, 06:44 AM

On My 1980 MB 300d the instrument lights/console lights are not lighting up after replacing fuses and all bulbs. (I just aquired this car) it was suggested that I check the light adjuster (variable rheostat) at the bottom of the cluster. My question is .. where is it located? I dont see it on the front and I dont see it on the back either. Is there even one on this car?If so ... where?
Thank you for your help !!!

NormanB · #4 09-25-2003, 11:00 AM

Quote:

Originally posted by bradkid6
I have replaced all the bulbs in the clusters and checked the main fuses . So all of those are good as far as I know.
I

I think there is also a fuse at the back of the instrument panel (is in mine anyway!) in the vicinity of the bulbs, looks a bit like a top hat normally red in colour. It is a push fit and can be quite tight.

#5 09-25-2003, 10:21 PM

I have a 1980 MB 300D that I recently aquired. The instrument lights (ones for night time driving) are not working. All other lights are working on the dash, ie, glow plug /turn signal/E Brake/seat belt lights.
I have replaced the bulbs /checked fuses /checked connections, and so far nothing.
I would really appreciate the help of anyone who has had a similar problem or has the technical expertise to suggest other things that I could try .
Thank you ALL for your help !

Randy

Palangi · #6 09-25-2003, 10:48 PM

In the row of warning lights (battery, seat belt, brakes, etc) along the lower edge of the instrument cluster, there should be 2 little knobs about 1/4 inch diameter. The one on the right adjusts the clock. The one on the left is the instrument light rheostat. With the speedometer at rest, the speedo needle will be more or less pointing at the rheostat. Also, when you push that knob, it resets the trip odometer. (Don't push it when the car is in motion.) It's 99% guaranteed that your lighting problem is because the rheostat is dirty. Just keep rotating it back and forth until the lights want to stay on. You will find that you need to do this 2 or 3 times a year.

brookspw · #7 10-08-2003, 03:03 PM

It appears that there is a bulb in the upper left and the upper right portions of the cluster.

The one on the right side is out on my cluster.

I suppose I can rule out the rheostat on that?

Also, my trip odometer "sticks" at 99.9 miles. It just clicks and clicks but can't get over it to 100.0. It will reset and go back to 0 and is fine for 99.9 miles. Just wondering since it is the same button.