Manual A/C

Test Conditions:
- Condenser and radiator clean and free of obstructions (clean if necessary)
- Ribbed belt in good condition and properly tensioned
- All air ducts, covers and seals are OK and correctly installed
- Car not parked in direct sunlight
- Engine at normal operating temperature
- Evaporator housing and heater box do not draw secondary air (at high fresh air blower speed)
- With engine running, A/C compressor switch and recirculation button pressed, both switch indicator lamps come on
- A/C compressor switches on (compressor clutch engages)
- Fresh air blower runs
- Coolant fan runs
- Recirculating/fresh air flap in "recirculating air" position

Checking:

Temperature Chart:

A - Outlet air temperature from center instrument panel vent
B - Outside (ambient) air temperature
C - Permissible tolerance range

- Outlet air temperature from center instrument panel vent must lie within tolerance range of chart at left after A/C has run for 5 minutes.
- Close hood.
- Measure outside (ambient) air temperature.
- Close doors and windows.
- Switch ignition on.
- Press A/C compressor switch and recirculating button. Both indicator lamps will come on.
- Set temperature control knob to maximum cold position and open all instrument panel air outlets.
- Switch fresh air blower to high speed (position 4).
- Set air distribution knob so that air flows from instrument panel vents.
- Start engine (begin time measurement).
- Increase engine speed (RPM) to 2000.
- Measure outlet air temperature from center instrument panel vent.
- Compare temperature readings with chart at left after A/C has run for 5 minutes.
- Temperature must be within tolerance range indicated

If not:
- Remove A/C refrigerant low pressure switch -F73- and bridge connector terminals.
- Remove A/C refrigerant high pressure switch -F118- and reconnect to connector.
- Connect A/C manifold gauge set to high and low pressure service valves.
- Start engine.
- Connect VAG1551 scan tool to Data Link Connector, DTC Memory, Checking and Erasing
- Select "Read Measuring Value Block" function 08 and input display group number 1 (001). Read Measuring Value Block (VAG 1551 Function 08)
- Check A/C cooling performance again, check display field 1 on scan tool, and check A/C system pressures.