Climate Sensor on Dash not "clicking"/AC blows HOT
1982 Mercedes W123 300D Turbo Diesel
1982 W123 Turbo Diesel
Recently, my AC started blowing extremely HOT (hotter than the normal heat). No matter what settings I change and which buttons I click, it blows HOT. It blows HOT with all buttons.
I also noticed that the climate sensor on the dash that usually "clicks" when I rotate the temperature wheel is not "clicking" anymore and is silent.
Note: for a long time now (years and years), in order to get any of the buttons to work, I usually have to click the defrost button first and then the other buttons will engage and work. Not all the time, but most of the time.
I have a newer compressor (less than 2 years) and my blower motor is working and I can hear the compressor engage when I click the AC button (it just blows extremely hot).
I checked all the fuses and they seem fine.
Coincidentally (or not), this started happening the day after I did two things to my Mercedes: 1) I took apart and replaced the rubber bumper fasteners (mounts) under my air filter housing unit. 2) Replaced the front shock absorbers.
Could either of these two things have anything to do with this problem with my AC? Could I have jarred or bumped anything in the same proximity to any AC stuff causing this extreme heat?
Many thanks for any suggestions, help and guidance. I've already done a lot of research online, but I just don't know where to begin (aside from taking it to a shop for diagnosis, which is the next step if I get stumped here).