I have a Fiat 500C. I am having issues with the HVAC. I have multiecuscan and it will not connect to the climate control module. I have checked all of the fuses and replaced the cig lighter fuse. It will connect to all other modules with the yellow adapter. The climate control all works except for the ac. The car only has 42k. I pulled vacuum on the system and it held fine. But the compresor clutch does not seem to engage. I tried jumping the relay. But did not hear the clutch engage. The snowflake is lit. Should i just replace the HVAC module or does it only interface with 500s with automatic ac. Im thinking it's either the compressor or the hvac module.