Heat Controller SMA Service Manual page 44

SMA/SMH09/12SC
Check Voltage black to red ‐35 volts ‐ motor voltage / black to blue ‐12 volts ‐control voltage
Low Voltage Disconect the plug on the pcb recheck the voltage if the volts are within specs
and when you plug it back in it's low then it is an evaporator problem
If nothing comes on disconect the red wire if it's the motor the condensor will come on
Always check that the numbers and the wire colours are correct on field and factory wiring