Förfarande och arrangemang för uppvärmning av ett med retader försett motorfordon

摘要

A motor vehicle is provided with a hydraulic retarder (5) which during vehicle operation is cooled by the engine coolant and thereby heats the latter. The vehicle's air-conditioning system (19) can via a control unit (9) for the retarder cause the latter to be switched on for heating purposes when the coolant temperature is too low to meet the heat requirement of the air-conditioning system at the time. The control unit decides whether and when switching on can take place.