The "sample blower motor" attached on the right side just inside of where the glove box is. If yours is in the same place, you remove the glove box and should see (with a light) a hose similar to a garden hose attached to the sample blower motor. Following LB's advice I followed the hose, pulled the motor from its mount, removed the hose and was able to observe it working. The hose runs up to the sensor near the ceiling light you mentioned. Still following the advise, I inserted a hose within the one removed from the sample blower motor and blew on it to see if air flowed to the sensor. It did. I put a piece of tissue where the hose connects to the blower and it barely held the tissue in place (should hold it as it should up at the sensor).

If you have the KLIMA behind the battery SB mentioned searching for the Ice Cube relay bypass. I never had to go that far (yet) since switching the ICE Cube relays (under the cover behind the fuse cover) around and cleaning the KLIMA contacts and putting dielectric compound on them did the trick getting my compressor to run again. Wish I knew which of the many little things I did helped but I don't. I'll certainly follow your post.

Might I suggest that you get your hands on the Mercedes Service Manual Automatic Climate Control. I just received mine and have started preparing to go through their procedures. Between it and the posts here on the forum, I am going to be replacing all of the pods behind the dash. Lots of good posts on that.

Use the search and you should find four posts on here that have substantial details on these ticklish systems.

__________________
Steve
'87 300TD - 132K - Soon 4-Sale
'84 300D Turbo - 122K - Driving
'77 VW Type II - 77K - Restored
'08 250EX Ninja
English Bulldog (Brier) - My best friend. Passed away 12/02/04 while in my arms.