Is taking the wiper assembly out on this model particularly difficult or unusual? If so why or how so? I just removed mine on my 126 and it was pretty simple and straight forward.
As to the ticking sound my fan had ingested a stray couple of pine needles that where at the root of the problem. I ended up removing the fan/motor and a quick cleaning did the trick. getting to it from under the dash wasn't exactly easy but certainly doable in a couple of hours. Don't know about this model but I think the earlier 123 cars where accessed from the wiper assembly bay area. Good luck!
Yeah I've checked out that site what he's got there is pretty informative and well done. But that goes to my point, it seems much easier to get at this blower motor from the outside than from the under dash area like in my 126. Breaking the windshield doesn't seem like much of a risk! Maybe if you drop a ratchet or wrench or something, maybe if your banging you head on it a little as you maneuver those metal clips! Seriously paying a tech for two and a half hours, I'd try it myself and reap the benefits of the lessons to be learn and save a couple of hundred bucks! Having someone else do the job ends up being a $400+ to fix after labor and MB parts to fix an annoyance!