ok, i've ran Fiat ECU Scan and got the following error
B1973 - Climate control compressor
The air conditioning relay or control circuit is faulty. Check the relay and the wiring from the control unit for opens, shorts and weak connections.
The reason for this fault is that ECU did not receive signal from the sensor. The fault is present now. Take appropriate action to fix this sensor fault. Dashboard warning light was not activated for this fault.
I've checked the fuses again and all ok, plus swapped the air con relay with the Horn relay and still the same message after clearing the code. if it is the pressure sensor at fault where is it located as i cannot see it clearly?