Mercedes-Benz ML320. Manual — part 654

NOTES ON HANDLING REFRIGERANT R134A - AH83.30-N-0003-01A

Air conditioning with refrigerant R134a

The refrigerant R134a is colorless and odorless.

At normal temperatures it is neither toxic nor flammable, and will not explode in the air, no matter what its
mixing ratio.

The R134a refrigerant may only be used in air conditioning systems for which R134a has been specifically
approved.

The refrigerant R134a must not be mixed with other refrigerants (e.g. R12).

The refrigerant R134a does not contain any chlorofluorocarbons (CFC). In contrast to other refrigerants (e.g.
R12) it is not hazardous to the environment at normal temperatures. The refrigerant R134a does not damage the
earth's ozone layer.

Despite these benefits, refrigerant R134a may only be extracted by experts with suitable extraction, recycling
and filling equipment that includes integral disposal and reprocessing capabilities.

CONDUCT IF AIR CONDITIONING SYSTEM IS DAMAGED OR LEAKING - AH83.30-N-0004-01A

All models

The air conditioning system should never be operated if it is damaged or when there is evidence of refrigerant
loss.

In the event that refrigerant is lost, lubrication can fail. This will lead to damage of the refrigerant compressor.

Evacuate damaged and/or leaking air conditioning refrigerant circuits as quickly as possible using extraction,
processing and recharging equipment with integral disposal and reprocessing capabilities.

PROTECT AIR CONDITIONING CIRCUIT AND COMPONENTS FROM MOISTURE WHEN CARRYING OUT REPAIR
WORK - AH83.30-N-0005-01A

Protect air conditioning circuit and
components from moisture when carrying
out repair work

MODEL 240

AH83.30-P-
0005-01H

Protect air conditioning circuit and
components from moisture when carrying
out repair work

MODEL 164, 199, 203, 209, 251 ...

AH83.30-P-
0005-01P

Protect air conditioning circuit and
components from moisture when carrying
out repair work

MODEL 199

AH83.30-P-
0005-01SLR

Notes on removing and installing the air
conditioner housing

MODEL 209, 463 ...

AH83.30-P-
0006-01GM

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me

All models fitted with air conditioning

Do not carry repair operations out on the air conditioning circuit in the open air during moist weather.

Moisture in the refrigerant circuit reduces the system's refrigeration output and leads to damage to the
components. The acidic substances produced by moisture within the system decompose the desiccant in the
fluid reservoir and damage the entire system.

After separating/unscrewing refrigerant lines, immediately seal off the connection openings so that they are
airproof using suitable stop plugs (parts kit).

Replace the fluid reservoir every time you open up the refrigeration circuit.

Always store all spare components in a dry, sealed-off area. Do not remove stop plugs in new components until
just before they are installed. Use special care when handling the receiver/dryer with its integral desiccation
unit.

When a receiver/dryer is left open, the dryer unit quickly becomes saturated with moisture, rendering it useless.

Check drier cartridge packaging for damage. Dispose of drier cartridges with damaged packaging.

Install the desiccant cartridge no later than 20 minutes after opening the packaging.

Further protection against moisture is provided by carefully evacuating the air conditioning system following
repair operations. By generating vacuum in the system, the evacuation process removes any moisture that might
have penetrated into the system.

NOTES ON RETROFITTING AN AIR CONDITIONING SYSTEM - AH83.30-P-0001-02A

Do not remove the plugs on any of the components until immediately prior to installation.

Fit all AC lines with new sealing rings. Coat thread and sealing rings with compressor oil.

BASIC KNOWLEDGE

VENTILATION, FUNCTION - GF83.10-P-2000GH

MODEL 163 up to 31.8.01

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me

Fig. 1: Identifying Ventilation System Function

Function

The ventilation system ensures:



that the windshield and windows are kept without mist.



there is a supply of fresh air to the vehicle occupants.



that constant and pleasant temperatures are quickly achieved in the vehicle interior.

Ventilation is achieved with the assistance of the blower motor (M2) during normal operation, when vehicle is
stationary or to increase the air quantity.

Fresh air is drawn into the heater housing via the air inlet. Depending on the control module setting, the air is
directed through the air ducts to the air vents in the interior.

The air flows out of the vehicle again through the rear vent via ventilation slots to the left and right in the area
below the rear side windows.

In recirculating air mode, air is drawn out of the interior of the vehicle through the recirculating air flap by the
blower motor (M2), and passed to the heater housing.

Air inlet, location/function

GF83.10-P-
2138GC

Air ducts, location/task/design

GF83.10-P-
2139GH

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me

VENTILATION, FUNCTION - GF83.10-P-2000GI

MODEL 163 as of 1.9.01 with CODE (580a) Automatic air conditioning

Air distribution duct

The air distribution duct and the existing air outlets for ventilating the vehicle interior are shown by the arrows.

Temperature-controlled air flows out of all the air outlets (red/blue arrows).

Rear vent, location/task/function

GF83.10-P-
2143GC

Defroster vent, location/task/function

GF83.10-P-
2144GC

Center nozzle, location/task/function

GF83.10-P-
2149GC

Lateral nozzle, location/task/function

GF83.10-P-
2150GC

Front footwell air outlet, location/task/function

GF83.10-P-
2145GC

Rear footwell air outlet, location/task/function

GF83.10-P-
2146GC

Blower, location / task / design / function

GF83.10-P-
2102GC

Series resistor group, location/task/function

GF83.10-P-
2161GC

Dust filter, location / task / function

GF83.10-P-
2142GH

Fresh air/recirculation flap, location / task / function

GF83.20-P-
2111GC

Recirculating air switch, location/task/design/ function

GF83.10-P-
2117GH

Fresh air/recirculation flap actuator motor, location /
task / function

GF83.30-P-
2116GC

Blower switch, location/task/design/function

GF83.25-P-
2100GC

Air distribution switch, location/task/design/ function

GF83.25-P-
2101GH

Heater housing position/task/function

except in the case of

code 580

GF83.20-P-
2110GC

Evaporator housing, location/task/function

for code 580 only

GF83.30-P-
2119GH

2001 Mercedes-Benz ML320

1998-2005 HVAC Climate Control - 163 Chassis

me