Hey there,

I had the same problem with the non-functional dash lights. I planned on
trying the jumper wire temporary repair, and in fact did have one soldered on... until I became curious as to why the stock rheostat failed.
I took it apart. The two contact springs looked good, and the rheostat coil wire looked good. The only obvious problem was rather heavy green oxidation. So I got some lemon concentrate out of the fridge, put the rheostat body in a cup, and covered it with the lemon juice. I swirled it around once or twice, then let is sit for 15 minutes in the lemon juice, along with the contact piece. After this, I removed them from the juice, and covered the parts with table salt. I used a toothbrush to scrub both parts for about a minute each. They were obviously clean, so I rinsed in hot water, blew them off with the compressor, and re-installed. Yep, it works fine now, rheostat fully functional again. So I reckon I made almost
$100 today in paying myself for cleaning that part rather than throwing money at the problem.
It would have been perfect if my daughter had managed to bring the right replacement bulb i needed. She got close! I just couldn't find the part
# for the actual instrument lamps. Removing the the cluster is so easy on the 240D I'll replace the lamp at the auto parts store, on the spot!
I'm not saying this will work for everyone's problem, but I am sure there has got to be a few folks out there that will benefit form trying this...


Stan