Volkswagen Golf / Golf GTI / Jetta. Manual — part 981

87-131

A/C refrigerant system,
troubleshooting

Requirements

Electrical systems OK

Air flow distribution systems (controls and

cables) OK

Correct and repair as necessary before

proceeding.

If any one of the following system conditions

exists, check A/C refrigerant system pressures

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A/C does not cool (cooling has stopped

completely)

Insufficient cooling during all driving speeds or

engine speeds (RPM)

No cooling or insufficient cooling after a period

of driving

A/C refrigerant system, troubleshooting

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87-132

Compressor noisy

- Tighten compressor and compressor bracket

mounting bolts using torque wrench.

- Check routing of A/C refrigerant hoses and lines;

hoses and lines must not contact other
components and must be installed without
tension or kinks, reposition or realign as
necessary.

A/C compressor noisy immediately after

switching A/C ON and/or when driving around
corners or braking (refrigerant shock)-system
overcharged

- Discharge A/C refrigerant system

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, then evacuate and recharge

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129

.

With an otherwise properly operating A/C

system, water sprays out of instrument panel
vents

- Check evaporator drain pipe for proper routing

(should not be kinked or pinched).

- Check evaporator water drain valve.

Must not be plugged with wax, dirt or

undercoating (clean if necessary)

Valve flap must open/close properly

- Check plenum tray.

Must be properly installed and not damaged

A/C refrigerant system, troubleshooting

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A/C refrigerant system pressures,
checking

Check A/C refrigerant system pressures using

these three tests:

1 - Air temperature drop from center instrument

panel outlet (A/C system cooling performance)

2 - A/C system high pressure

3 - A/C system low pressure

The combined results of all three steps

determine which part of the A/C system is
causing the problem, see table

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Test conditions

A/C refrigerant system fully charged; discharge,

evacuate and recharge system if necessary

Condenser and radiator clean and free of

obstructions (spray clean if necessary)

Air distribution can be adjusted correctly using

control knobs (all air distribution flaps reach end
positions)

Wiring OK per wiring diagram

Outside (ambient) air temperature between 20-

30 C (68-86 F)

Drive belts for A/C compressor and Generator

in good condition and properly tensioned

A/C refrigerant system, troubleshooting

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Test 1: Air temperature drop from center

instrument panel outlet, checking (A/C
system cooling performance)

- Start engine.

- Set temperature control to maximum "cold" (if

manual A/C) or "LO" (if Climatronic).

- Manual A/C: Press "A/C" button and select

second blower speed.

- Climatronic: Select minimum blower speed

(manual override)) by pressing "decrease blower
speed" button (observe blower speed display in
control head).

- Adjust air distribution to instrument panel

outlets.

- Insert thermometer into center instrument panel

outlet and raise engine speed to approximately
1500 RPM.

Specified result

With humidity normal and outside (ambient)

temperature between 20-25 C (68-77 F),
system is cooling satisfactorily if air temperature
from center instrument panel vent drops below
10 C (50 F) within 1 minute.

For higher ambient temperatures and/or higher

humidity, specified air temperature from center
instrument panel vent can be slightly higher.

If specified reading is not obtained, perform tests

2 and 3, then compare results of all three tests

table,

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A/C refrigerant system, troubleshooting

13/2/2005