Good news and bad news relating to my 1999 C Class heater switches.
I decided my heater blower was faulty because of the switch. When the car was left overnight the blower wouldn't work. After pushing and pulling on the switch a few time it would come on and work all day. Yesterday I took the electronic switch assembly out and gave it a good soaking in 'switch cleaner' (available from all good electrical shops) paying particular attention to the electronic rotary switch in the centre of the blower dial. (You need to first split the plastic housing until you can see the printed circuit board).
I reassembled and replaced the assembly and 'hey presto' it works better than ever. Problem solved.
Now the bad news:
One of the backlight led's has stopped working and i'm not sure if it can be replaced. The pcb looks like it may come away from the rest of the plastic framework and the bulb pull out but I don't want to force it in case I wreck the thing.
Has anybody done this. It's a shame to have to replace the whole unit after me fixing it but not having illuminated switches at night is really irritating.
KW