[Clan]

Have you checked with a test light that there is a good feed to the clutch when the engine is driving and compressor not working ? Does the clutch disengage when you rev the engine?

The Engine ECU is in control of the Compressor not the climate module directly . it operates the compressir relay when it gets a request from the climate module and as it monitors the AC pressures only when the pressures are right . Perhaps the pressure is too high? ie. wrong gas ? R134a is the gas . Wrong compressor with too high a capacity ? You said it was not a volvo specification compresssor ...