Heater Box and Evaporator Housing, Assembly

- Heater repair information. Heating and Air Conditioning
- Refrigerant system components.Description and Operation
- Vacuum hose layout. Vacuum and Vapor Hose Diagrams
- Check Diagnostic Trouble Code (DTC) memory using VAG 1551 scan tool.
- A/C system cooling performance, checking. Testing and Inspection





1 - Engine coolant shutoff valve
- Closed when vacuum is applied
2 - Check valve
3 - Vacuum reservoir
4 - Fresh air blower series resistance -N24-
- Manual A/C only
- Housing color: orange
5 - Fresh air blower -V2-
6 - Heater box
7 - Engine coolant two-way vacuum valve -N147-
8 - Clamp
9 - Coupling hose
10 - Evaporator water drain hose
- Route hose straight and kink-free
- Ensure hose connections are tight and sealed
11 - Evaporator water drain valve
- Clean any dirt, wax or under-coating from valve flap, valve flap must close
- Ensure hose connection to valve is tight and sealed
12 - A/C refrigerant low pressure switch -F73-
13 - Ambient temperature switch -F38-
14 - Evaporator
- Discharge A/C refrigerant system before removing
15 - Recirculating air flap
16 - Fresh air/recirculating flap vacuum motor
17 - Fresh air flap
18 - Fresh air/recirculating flap two-way valve -N63-
19 - Central flap Bowden cable (for footwell/defroster and instrument panel air outlets)
- Manual A/C only
20 - Temperature flap Bowden cable
- Manual A/C only
21 - A/C and heater control
- Manual A/C only
22 - Recirculating mode button in A/C switch -E30-
- Manual A/C only
23 - A/C compressor ON/OFF switch in A/C switch -E30-
- Manual A/C only
- Switches A/C compressor ON and OFF
24 - Engine coolant shutoff valve switch -E151
- Manual A/C only
- Closes coolant shutoff valve via two-way valve -N147- when "Max. cold" of temperature knob is selected
25 - Heater A/C wiring harness