Defroster blower, AC, vents?

[MathewHennessy]

Hi,
I'm wondering how I would go about diagnosing an issue with the climate control to see whether or not I need to bring my 1987 300SDL in for some expensive service.

For awhile now (definitely since Jan/Feb of this year) the defroster blower never works. That is, I hit the defroster button even after the car is totally warm, and the sucker never blows high-velocity air as it is supposed to. I've also noticed that the clicking of vent baffles behind the dashboard I usually hear when switching the vent controls (from, say, economy to full A/C) hasn't been happening. Now that it's super hot out, I've also noticed that I am getting _zero_ blowing of AC regardless of temp setting (COLD), fan or A/C setting. However, when it's not that hot out, I can feel some cold air sneaking out the vents but when it's >90 degrees like it was today I felt nothing.

So, my question is, what can I check first, with a normal set of tools (screwdrivers, drill, socket wrenches, voltmeter, Cold Heat(tm)) to see if I can fix this before handing it off to the pros? I've replaced various bulbs and fuses, and diagnosed and replaced the glow plug relay fuse thanks to help from the Intertron, but I don't have any jacks, lifts or any sort of professional tools readily available.

TIA!
- Matt (1987 300SDL, 398k mi)

[sixto]

It's not difficult to replace the climate control unit. You can try resoldering the unit but it's difficult to take apart and folks haven't had much luck with resoldering solving ACC problems.

But start with checking the blower motor. Instructions are in the archives. Or be adventurous and take off panels until you see the blower (ahead of the glove box).

Sixto