Converting W115, W123, W126 instrument cluster lighting.
 

Got tired of the dim instruments lighting in my cars. By-passing the rheostat and freshening up the needles helped but the available light was poor at best. I guess my old eyes are just tired.

Decided to switch to LED's.

Stock/OEM lighting.

Attachment 152679

Single LED on right, OEM on left. BIG difference in visibility!

Attachment 152680

Tried the single LED's for the lighting. Better but had a couple of less lit areas. Note the center of the speedometer and the outer edges of the gauges.

Attachment 152681

The 5 LED bulb on the left, the single LED on the right. Just wanted a comparison.

Attachment 152682

The stock 194 bulbs replaced with the comparable 5 LED bulbs.

Attachment 152683

A plus is the fact the 5 LED bulbs raised the temperature of the cluster mounting to 128 F after a steady hour of use whereas the standard bulb raised the temperature to 165 F after only five minutes of use. Them little suckers were toasty to my fingers when I changed them.

Battery voltage was at a steady 12.7 Volts. I used my CTek charger on the maintenance mode to ensure a constant voltage.

Before anyone asks, no, that is NOT the correct mileage. The speedometer had been repaired/replaced in '08 at 161xxx miles and hadn't worked in who knows how long or was even correct. Wasn't working when the present owner bought the car and when I repaired the odometer gear I inadvertently rolled back the odo one complete digit (add 111111 to the reading). Didn't notice it until after I had the cluster re-assembled. Not having the records to the car I wasn't going to pull it all apart again since there is no way anyone would believe the car has only 165K on it. I'd peg the car at 200 K+ simply due to the amount of work I've done to it.

The small glare/reflection of lights above the cluster is due to the panel not being seated fully into the dash.

I posted in another thread what needs to be done to use the standard 194 bulb in the W115, W123 and W126 chassis. Probably the same for the W107 and the W116.

Post #4

http://www.peachparts.com/shopforum/vintage-mercedes-forum/399341-w115-change-replacing-rear-bulbs.html

I can't speak for all of them, but the light setup on my R107 is very different from the W126. It uses no "light pipe" and instead uses a very long lamp holder with the tiny "grain of rice" style bulb fitted. Unlike the 123/126 setup, it provides more than adequate light with the stock setup with the rheostat bypassed.

Well, scratch the 107's off the list then. Thanks for the heads up.

The W116 appears to use the same lighting setup as the R107 so eliminate it also.

https://**************.com/problems/lights/instrument-cluster-light-bulb-requirements
Mercedes source site. Blasted URL editor!