MBdiesel,

Hope this isn't a hijack and has some relevance to your issue. I am dancing around a similar -maybe same - problem on my car ( a 93 300SD). In very hot weather - above 95* - I turn the ignition key and sometimes only the airbag light comes on. No other idiot lights, no starter crank, nothing. This happened last year in our annual NC heatwave. The stealer wanted about $1000 to replace the ignition switch assembly. I passed at that offer and bought another car.

The weather cooled and for most of last year I drove it occassionaly when I had a local round trip and would not shut it off until I got back home. I was 100% successful in having it start. This year the annual heat wave hits again, again no start. The weather has just cooled off and I am again learning to "trust" it.

Is this similar to your conditions or do your idiot lights come on and just no cranking? This seems to be the next project on this car. Then back to determining if the turbo rebuilt significantly helped the oil consumption problem... but that is another post.

Chuck