Christi@n

There's the red/blue arrow switch to regolate cab temperature, sometimes my red side (right side switch) doesn't respond, blue always respond without any effort.

Can it depend from coolant temp, some other sensor around the car, or should I assume a bad switch?

PatternDayTrader

The control head is screwed up. It should be repairable though. Your going to have to disassemble it, then clean the switch contacts. There are several threads about this issue already, in case you feel like using the search function for this site.