Mercedes-Benz ML320. Service manual - part 666

The fresh air/recirculated air flap shuts off the supply of recirculated air.

Fresh air is drawn in. 

Recirculation mode  

The fresh air/recirculated air flap shuts off the supply of fresh air. Air is drawn in from the passenger 
compartment. 

HEATER CORE, LOCATION/PURPOSE/FUNCTION - GF83.20-P-2108GC 

MODEL 163, 168  

HEATING WATER CIRCULATION PUMP, LOCATION/TASK/FUNCTION - GF83.20-P-2109GI 

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

Fig. 41: Identifying Heating Water Circulation Pump 

 

Heater core, 
location

Model 168

GF83.20-P-
2101-02GC

   

Model 163

GF83.20-P-
2101-02GH

 

Heater core, 
purpose

The heater core serves for heating up the air flowing through on the way 
to the various defroster, ventilation and heating nozzles in the vehicle 
passenger compartment.

 

 

Heater core, 
function

 

GF83.20-P-
2101-01GC

 

Heating water 
circulation pump, 
position

The heating water circulation pump (M13) is located at the front 
right in the engine compartment next to the coolant compensating 
reservoir.

 

 

Heating water 
circulation pump 
task

The heating water circulation pump (M13) serves to maintain a 
constant flow of hot water through the heat exchanger in the event of 
low engine speeds and residual engine heat utilization.

 

 

2001 Mercedes-Benz ML320 

1998-2005 HVAC Climate Control - 163 Chassis

  

me 

 

HEATER HOUSING POSITION/TASK/FUNCTION - GF83.20-P-2110GC 

MODEL 163 up to 31.8.01  

168 up to except CODE (580) Air conditioning or Tempmatic for USA  

Shown on model 168 as of 1.03.01  

Fig. 42: Identifying Heater Housing - Shown On Model 168 As Of 1.03.01 

FRESH AIR/RECIRCULATED AIR FLAP, LOCATION/PURPOSE/FUNCTION - GF83.20-P-2111GC 

MODEL 163, 168  

 

Heating water 
circulation pump 
function

 

GF83.20-P-
2102-01GI

 

Heater housing 
position

The heater housing (1) is located beneath the instrument 
panel.

 

   

Model 168 up to 28.02.01

GF83.20-P-2103-
01GC

   

Model 163

GF83.20-P-2103-
01GH

  Heater housing task

 

GF83.20-P-2103-
03GC

 

Heater housing 
function

Model 168

GF83.20-P-2103-
02GC

   

Model 163

GF83.20-P-2103-
02GH

 

2001 Mercedes-Benz ML320 

1998-2005 HVAC Climate Control - 163 Chassis

  

me 

 

BLOWER SWITCH, LOCATION - GF83.25-P-2100-01GH 

Heater depiction  

The blower switch (1) is located in the heater control unit. 

Fig. 43: Identifying Blower Switch On Heater Control Unit 

BLOWER SWITCH, FUNCTION - GF83.25-P-2100-02GC 

Function  

Depending on the setting of the blower switch, the current is guided via sliding contacts onto a contact plate, 
and from there to the relevant series resistor assembly resistor for the set blower level. 

On actuation of the starter, the control voltage for the blower (M2) is switched off at the control unit via 
terminal 15x. 

Model 168 as of 1.03.01  

Blower level 4 is implemented by bridging two contact decks. 

 As a result of the design of the contact plate, the re-activation of 

blower level 1 --> blower level 2 and 

 

Fresh air/recirculated air 
flap, location

Model 168

GF83.20-P-2104-
01GC

   

Model 163

GF83.20-P-
2104-01GH

 

Fresh air/recirculated air 
flap, purpose

The fresh air/recirculated air flap switches the system 
over from fresh air to recirculated air.

 

 

Fresh air/recirculated air 
flap, function

Model 168

GF83.20-P-2104-
02GC

   

Model 163

GF83.20-P-
2104-02GH

 

2001 Mercedes-Benz ML320 

1998-2005 HVAC Climate Control - 163 Chassis

  

me 

 

blower level 2 --> blower level 3 

may lead to an increase in the speed of the blower motor due to the short-term bridging of two contact plates 
(intermediate setting). 

BLOWER SWITCH, LOCATION/TASK/DESIGN/FUNCTION - GF83.25-P-2100GC 

MODEL 163 up to 31.8.01 168  

Shown on model 168 with heating as of 01.03.01  

Fig. 44: Identifying Blower Switch (Model 168 With Heating As Of 01.03.01) 

BLOWER SWITCH, LOCATION/TASK/DESIGN/FUNCTION - GF83.25-P-2100GI 

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

 

Blower switch, 
location

The blower switch (N119s3) is located on the left in the heater 
push-button control module.

 

   

Model 168 up to 28.02.01

GF83.25-P-2100-
01GC

   

Model 163

GF83.25-P-2100-
01GH

 

Blower switch, 
task

The blower switch activates several blower stages in fresh air 
and recirculating air mode.

 

 

Blower switch 
design

The blower switch is designed as a multi-level rotary switch with 
an axis and wiper contact.

 

 

Blower switch, 
function

 

GF83.25-P-2100-
02GC

 

2001 Mercedes-Benz ML320 

1998-2005 HVAC Climate Control - 163 Chassis

  

me