Mercedes-Benz ML320. Manual — part 685

ENGINE 111, 112, 271, 272, 611, 612, 646 in MODEL 203.7 with CODE (580) Air conditioning (or
Tempmatic for USA) with CODE (580) Automatic air conditioning with CODE (581) Automatic air
conditioning with CODE (581) Comfort automatic air conditioning

ENGINE 112.942 /970, 113.942 /965 /981, 612.963, 628.963 in MODEL 163 as of 1.9.01 with CODE (580)
Automatic air conditioning

ENGINE 112, 113, 271, 272, 273, 612, 642, 646 in MODEL 209.3

ENGINE 112, 113, 271, 272, 273, 642 in MODEL 209.4

Shown on model 203

Fig. 105: Identifying Refrigerant Compressor - Shown On Model 203

ELECTROMAGNETIC CLUTCH, FUNCTION - GF83.55-P-2101-01A

Electromagnetic clutch (A9k1)

Refrigerant compressor,
position

The refrigerant compressor (A9) is flange-mounted to the
left front of the engine.

Model 163

GF83.55-P-2100-
01GH

Refrigerant compressor,
task

The refrigerant compressor (A9) is responsible for induction
and compression of the refrigerant.

Refrigerant compressor,
design

GF83.55-P-2100-
03P

Refrigerant compressor,
function

GF83.55-P-2100-
02P

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me

Fig. 106: Identifying Electromagnetic Clutch (A9K1) Components

Function

In order to start operating the refrigerant compressor, the push-button control module (N19, N22) actuates the
electromagnetic clutch (A9k1) and the solenoid (5) is supplied with electrical current. The magnetic force
attracts the pressure plate (6) against the rubber insert (7) and holds it securely. This creates the frictional
connection between the automotive engine and the refrigerant compressor. If the solenoid (5) is de-energized,
then the pressure plate (6) is pressed back by the rubber insert (7) into its rest position and the frictional
connection is interrupted.

Safety shutoff of the refrigerant compressor

To prevent a mechanical defect in the refrigerant compressor from causing the poly V-belt to jump loose, the
electromagnetic clutch releases itself automatically. With a mechanical defect, the refrigerant compressor
rotates more sluggishly or even locks completely. The heat generated at the friction surface causes the melting
fuse (2) in the solenoid (5) to melt. The current supply to the solenoid (5) is interrupted and the frictional
connection is released.

ELECTROMAGNETIC CLUTCH, LOCATION - GF83.55-P-2101-02GH

The electromagnetic clutch (A9k1) is located on the drive shaft of the refrigerant compressor (A9) at the front
left in the engine compartment.

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me

Fig. 107: Identifying Electromagnetic Clutch

ELECTROMAGNETIC CLUTCH, DESIGN - GF83.55-P-2101-03GH

The belt pulley (1) mounted on the drive shaft (4) of the refrigerant compressor is driven by the poly V-belt. It
rotates on the ball bearing (3), around the solenoid (5) attached on the refrigerant compressor housing. The
pressure plate (6) with the rubber insert (7) is connected via splining (8) to the drive shaft (4) of the refrigerant
compressor and is axially displaceable thereon.

Fig. 108: Identifying Electromagnetic Clutch (A9K1) Components

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me

ELECTROMAGNETIC CLUTCH POSITION/TASK/DESIGN/FUNCTION - GF83.55-P-2101GH

ENGINES 111.977, 112.942, 113.942/981, 612.963 in MODEL 163 up to 31.08.01 with CODE (580) Air
conditioning or Tempmatic for USA

Electromagnetic clutch (A9k1)

Fig. 109: Identifying Electromagnetic Clutch (A9K1) Components

REFRIGERANT COMPRESSOR CONTROL VALVE, FUNCTION - GF83.55-P-2102-02P

Electromagnetic clutch,
location

GF83.55-P-
2101-02GH

Electromagnetic clutch,
task



Switching the frictional connection between the
automotive engine and the refrigerant compressor



Switching off the refrigerant compressor with a
mechanical defect.

Electromagnetic clutch,
design

GF83.55-P-
2101-03GH

Electromagnetic clutch,
function

GF83.55-P-
2101-01A

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me