My Dad recently told me that his instrument panel is dark at night, and I realize that two light bulbs are supposed to cast light upon the panel. This is not "back" illumination through translucent characters, but dim white light cast upon the faces of the instruments from positions above. In other words, the light bulbs are located physically between driver and instruments.

I have verified that fuses are OK. I realize that a potentiometer dims the lighting, and if the potentiometer dies, the lights go out. Dad cannot recall if both lights went out simultaneously, which, admittedly, would implicate the pot.

I have seen another posting, describing the removal of an MB instrument panel, using homemade hooks, but this would be inappropriate. Dad's panel doesn't resemble that other panel.


The entire instrument panel is viewed through a transparent plastic barrier. I don't think I could get at the bulbs, even if that plastic barrier were absent. The bulbs seem to be recessed in the upper reaches of the dash structure.

Can anyone advise me on the proper method of accessing, and changing these bulbs?

Do I have to pull the entire dash board just to replace two light bulbs?

Are these bulbs incandescent, therefore likely to burn out?

Is the potentiometer notorious for failing?

Dad is the original owner of the vehicle, which has about 180,000 miles on it.

Any pictorials or links would be greatly appreciated.

...

The easiest way to get to the bulbs is to remove the cluster, which only takes about 10 minutes. Instead of using the hooks, remove the panel above the drivers knees and reach up behind the dash to push it out. There is nothing holding it in place except wires, an oil line, and the speedo cable. The bulbs are actually located at the back of the cluster with a "fiber optics" piece of plastic that transports the light to the front of the cluster. You may be able to pull out the bulbs without disconnecting the wires, oil line, or cable (depending how much slack you have in the cable) by just pulling the cluster partially out. It's fairly obvious once you see it. The bulbs are just standard little instrument bulbs that you can get at a parts store. If replacing the bulbs does not work, it's probably the dimmer. You will have to remove the cluster to either replace of bypass the dimmer if that's the problem.

Edit: If the problem is the dimmer, it would also affect the other dash lights on the heater controls and the switches.