IP lighting

[MS Fowler]

I have been chasing the lack on IP lights on my '82 300SD.

I printed out the page from my CD service manual.
The problem is that the pin outs do nor coincide with those shown in the FSM.
Can anyone provide the correct pin wiring for the instrument panel connections?
Thanks,

The problem is likely the Dash Light Rheostat on the back of the cluster is bad. Make a jumper wire and connect the two metal strips on the back of it. If the lights come on, you can either replace the rheostat or make a permanent jumper across the contacts.

[TimFreeh]

For a minute there I was scratching my head trying to figure out why Mercedes felt a need to illuminate the Injection Pump.

[Palangi]

Originally Posted by TimFreeh

For a minute there I was scratching my head trying to figure out why Mercedes felt a need to illuminate the Injection Pump.

It's so you can check the oil in the dark...

Originally Posted by TimFreeh

For a minute there I was scratching my head trying to figure out why Mercedes felt a need to illuminate the Injection Pump.

Same here.

[justinperkins]

Originally Posted by TimFreeh

For a minute there I was scratching my head trying to figure out why Mercedes felt a need to illuminate the Injection Pump.

Me too, still trying to figure out what IP means...

Boy those lights are dim though, does soldering the rheostat to permanent max wattage make it any brighter than twisting the dial to max?

I bet taking the cluster apart and cleaning everything would help. I should do that while I'm replacing the LCD (W124).

[MS Fowler]

Sorry about the illuminated injection pump.

It seems like a wierd way to wire the panel. Apparently, the feed from the light switch comes into the big round connector at terminal #5, goes across the rheostat and then out terminal #8 to somewhere in the wiring harness where it returns to the squatre electrical plug. The FSM says there are 8 connections, well, my car has only six. The terminals that are labeled #1 and #2 have no pins to connect, and no female terminals in the wiring block. So, while it is an 8 pin connection, only 6 are active. The top 3 connections go to left and right turn and the last one is the panel illumination.
I plan to bridge the lighting rheostat as I find fully "on" is barley bright enough.

What is the max Candle Power that can be used w/o burning/melting the Instrument Panel?

Originally Posted by MS Fowler

What is the max Candle Power that can be used w/o burning/melting the Instrument Panel?

Pretty much the 5w bulb that's in there. Even that can get hot enough to brown the reflector.

[barry123400]

There are quite a few threads about improving the illumination in the instrument panel IP? Worth looking at in the archives perhaps. Even just restoring the original lighting and reflective surfaces to their original glory is some improvement apparently. Some improvement needless to say is a lot and desirable with these particular clusters. Light emmiting diodes should have got around this deficiency but they were considered to have a poor light distribution pattern. This is a little strange as the fundemental complaint is poorly concentrated or unfocussed light with many applications for them. There may soon be a variation available that will help hopefully as for practical purposes they consume minimal current so produce virtually no heat. Plus a tremendous amount of light compared to the original bulbs is aailable from some of them.

[Knightrider966]

Originally Posted by TimFreeh

For a minute there I was scratching my head trying to figure out why Mercedes felt a need to illuminate the Injection Pump.

Me too! That one really had me going!!

[MS Fowler]

It turns out that there were two problems.
1) The rheostat was bad---I chose to solder a wire across the terminals as I always turn the lights to the brightest setting.
2) All the ibulbs were bad. I replaced them, and everything looks good.