A/C system, running after mounting compressor

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After installation of a new compressor or after adding fresh refrigerant oil to the compressor (e.g. after blowing out refrigerant circuit), give compressor approx. 10 turns by hand after installing and prior to initial start-up of engine (before installing belt or tightening drive shaft) to prevent compressor damage.
Assemble refrigerant circuit before starting engine.
Only start engine with refrigerant circuit full if at all possible.

NOTE:

Different compressors depending on country version, production period and engine → Refrigerant system, servicing
The compressor is always driven (by pulley or via drive shaft by engine); there is no A/C clutch.
The compressor is equipped with an "internal oil circuit" to prevent damage if the refrigerant circuit is empty. This internal lubrication is only possible if there is still a residual quantity of refrigerant oil in the compressor.
The engine must not be started unless the refrigerant circuit has been properly assembled. If, for example, the refrigerant lines have not been connected to the compressor, heat generation inside the compressor with the engine running may lead to destruction of the compressor.
The A/C Compressor Regulator Valve N280 is not activated if the refrigerant circuit is empty and the compressor runs at idle with the engine. However, as there is no refrigerant available, the refrigerant oil required for compressor lubrication is not conveyed. Compressor lubrication is maintained by way of an "internal oil circuit" to prevent damage.
If the engine has to be started when the refrigerant circuit is empty:
- Refrigerant circuit must have been fully assembled.
- Compressor must contain at least a quarter of the amount of refrigerant oil specified for this refrigerant circuit.
- Engine speed must not exceed 2500 RPM.
- Engine should not be left running for longer than is absolutely necessary.

Pay attention to the following on starting engine for the first time after charging refrigerant circuit:

Start engine with compressor switched off ("ECON" mode) and wait for idling speed to stabilize.
Open instrument panel vents.
On operating and display module, Climatronic Control Module J255, select "Lo" temperature setting for drivers and front passengers side.
Then switch on compressor ("Auto" mode) and allow it to run for at least 5 minutes with engine idling.