Yup, all sorts of problems.

I only get heat out the defrost vents, never to the floor or out the main vents. I only get heat some of the time, and only when the temp wheel is at what I presume to be Max (the wheel itself has no numbers so I can't tell what the temp should be.) It gets hotter than blazes when it's on, and adjusting the wheel for some other temp makes things awfully cold. The fan switches do seem to cause the fan to run in a way that seems right (i.e., on all the time, varying speed, and free wheeling).

In operation, I also hear some "clicking" that seems to be coming from the driver's right side, perhaps behind the glove box or footwell on the passengers side? It seems like that may be the "controller" trying to switch flapper valves around to regulate the temperature, but since there's no vacuum, the temp can't be regulated.

From the symptoms and the reading that I've done on the on the CD, I've concluded that I probably have a vacuum problem of some sort. I bought a MityVac and started troubleshooting today.

I've been pretty faithful about following the steps shown on the CD (83-620), So far I've found that

Step A
1) the check valve seems to be ok
2) the vacuum reservoir holds no vacuum at all

Step B
seems ok per the MityVac

Step C forward looses vacuum at all steps. I'm not quite sure what this means yet, but my guess is that there is probably a problem with the main vacuum supply line, maybe going to Y7? Since I couldn't easily find Y7 and it was getting too dark and cold late this afternoon, I decided to call it a day.

I'm also really disappointed with the expensive CD that I bought from MB. The detail on the pictures is horrible, both on screen and printed. I'd have thought that the quality would be better.

Thanks!

Sean