On the money ...
Hey Ross and Bryan ... BINGO!!!
After this morning's posts and after the market caught me on the wrong side of the move up today I went out at lunch and popped the hood. Following your suggestion I located the fuse strip (on the 400e it is about 4 inches in front of the main fuse panel) exactly as you described ... a thin rectangle with 2 heavy gauge wires feeding into each of the long ends of the rectangle. The top easily pops open back towards you. What I saw was a long metallic fuse strip (inch and a half or so). It was curiously bowed upward at the center, but apparently intact. As soon as I lightly touched it, it broke!! Went to the local dealer and got 3 of 'em ... at a buck twenty five a piece, by the way. Went out to the parking lot, popped the hood and in all of about 5 minutes the fan and A/C is working perfectly!!
As someone had posted earlier in the previous thread, it seems impossible for it to work intermittently ... the fuse is either broke or it ain't, the connection is either open or it's closed ... well, we now know that isn't necessarily so. Ve 'ave vays of making the dog chase his tail!!
I'm not mechanically proficient enough to understand this curiousity, maybe benzmac or one of the other experts can illuminate us ... but, for sure, don't dismiss the strip fuse as the culprit and run for the dealer service department. First check out Ross' and Bryan's discovery ... worked perfect for me. It's cold again, can you see my breath?
Thanks Ross. Thanks Bryan.