Your car no more resembles the uS model than it does a 240D. The US only gets the fully optioned car including automatic A/C. Since your car didn't come with any A/C you will not find a wiring diagram for it.
You will have to diagnose it by function. Are you saying that you want to have the compressor cycle more (at a higher temp) or are you wanting to mix heat with A/C? This will probably have to be done manually.
Bosch Master, ASE Master, L1
33 years MB technician