1990 VOLKSWAGEN CORRADO window

* ELECTRICAL SYSTEM UNIFORM INSPECTION GUIDELINES *
Article Text (p. 18)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:29PM
terminals ³ ³
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ´
³Damaged
³ ³
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ VEHICLE ACCESSORIES
Vehicle accessories refers to OEM installed equipment,
including but not limited to power windows, locks, seats, roof/top,
antennas, heated seats, mirrors, windshield/window defrosters, trunk
pull down/release, keyless entry, tire pressure monitors, electric
mirrors, etc.
POWER LOCKS, WINDOWS, SEATS, MIRRORS, ROOF/TOPS, ANTENNAS,
SLIDING DOORS
SWITCHES
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄCondition
³ Procedure
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄInoperable
³ Require replacement.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄIntermittent
³ Suggest replacement.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄMalfunctioning (e.g.,binding, worn,
³ Suggest repair or replacement.
won't return, etc.)
³
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄMissing
³ Require replacement.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄMissing, damaged mounting hardware
³ Require repair or replacement

³ of mounting hardware.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄCorroded, loose terminals
³ Suggest repair or replacement.
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄDamaged (e.g., melted, burned,
³ Suggest replacement.
cracked, etc.)
³
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÁÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ ACTUATORS/MOTORS/SOLENOIDS/TRANSDUCERS
ACTUATORS/MOTORS/SOLENOIDS/TRANSDUCERS
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄCondition
³ Procedure ³ Note
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄInoperative/
³ Require replacement. ³intermittent
³ ³
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄMalfunctioning (e.g.
³ Suggest repair or ³binding, worn, won't
³ replacement. ³return, etc.)
³ ³
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÅÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄMissing
³ Require replacement. ³

A/C-HEATER SYSTEM - MANUAL
Article Text
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PM
ARTICLE BEGINNING
1990 MANUAL A/C-HEATER SYSTEMS
Volkswagen
Cabriolet, Corrado, Fox, Golf GL, GTI,
Jetta, Jetta GLi, Vanagon
* PLEASE READ THIS FIRST *
CAUTION: When discharging air conditioning system, use only approved
refrigerant recovery/recycling equipment. Make every attempt
to avoid discharging refrigerant into the atmosphere.
AIR BAG WARNING
WARNING: To avoid accidental air bag deployment on Cabriolet, see AIR
BAG DEACTIVATION under SERVICING PRECAUTIONS in this article.
DESCRIPTION
The Volkswagen air conditioning system is a cycling clutch
type. The compressor is cycled on and off by a thermostatic switch to
maintain constant cooling rate.
Other components include an evaporator, expansion valve,
receiver-drier, control panel, condenser, high-pressure switch and a
low-pressure switch. On Vanagon, the A/C thermostat can be found on
left rear pillar, above relay panel assembly (behind trim panel).
The control panel includes a pair of levers and a fan control
switch. The upper lever operates air distribution flap. The lower
lever controls temperature selection. The rotary fan control switch
controls fan speed selection.
OPERATION
SYSTEM CONTROLS
Air Distribution Lever
When in A/C position, cool air is routed to registers and
side air vents. In BI-LEVEL position, cool air is routed to floor
vents as well as registers and side air vents. In HEAT position, warm
air is routed to windshield vents, side window nozzles and floor and
center registers. In DEFOG position, warm air is routed to windshield
vents, side window nozzles and side registers.
Fan Control Knob
The fan control knob controls airflow. As knob is turned
clockwise, air intake opens and fan operates, increasing speed as knob
is moved to extreme right position.

A/C-HEATER SYSTEM - MANUAL
Article Text (p. 5)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PM
MICROSWITCH
Loosen microswitch mounting screw. Move microswitch so switch
is on when lever is at maximum A/C, NORM (normal), BI-LEVEL or extreme
right position, and off when lever is at VENT or HEAT position.
Tighten microswitch mounting screw. Recheck operation.
TEMPERATURE SWITCH
Move temperature lever to full cool position. Loosen
temperature switch mounting screw. Move temperature switch
counterclockwise to full stop position. Tighten temperature switch
mounting screw.
TROUBLE SHOOTING
NO COOLING
1) Ensure fan motor operates in all 4 speeds, air duct closes
off outside air and heater water valve is closed. Adjust belt tension.
2) Inspect receiver-drier pressure seal. If seal is good, go
to step 5). If seal is broken, evacuate and recharge system. If system
cools properly, testing is complete. If system does not cool, connect
pressure gauges.
3) Set engine speed at 2500 RPM. Insert thermometer in left
register and close all others. Place controls on high blower and
maximum cooling. With vehicle out of direct sunlight, close all
windows. Radiator fan should come on with system pressure at 200 psi
(14 kg/cmý).
NOTE: If system doors allow air leaks, evaporator will freeze up
and testing will not be possible.
4) If fan does not operate, replace pressure switch. Ensure
system is okay. If fan does come on, turn engine off and check for
condenser obstructions and blocked airflow.
5) Turn air conditioner on and off with temperature control
lever. Ensure compressor clutch engages. Push lever to extreme right
position and back again. A click should be heard from compressor
clutch. If a click is not heard, check for voltage at clutch coil wire
with switch on. If voltage is present, replace clutch coil. If voltage
is not present, check wiring or replace thermostatic switch.
6) If compressor clutch operates, check gauge readings. If
both are low, locate leak and recharge system. If both are high,
replace expansion valve. If low side is too high and high side reads
too low, replace or rebuild compressor.
INSUFFICIENT COOLING
1) Ensure fan motor operates at all 4 speeds, air duct closes
off outside air intake and heater water valve is closed. Adjust
compressor belt tension and clean condenser.

A/C-HEATER SYSTEM - MANUAL
Article Text (p. 6)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:41PM
NOTE: If system doors allow air leaks, evaporator will freeze up
and testing will not be possible.
2) Adjust engine speed to 2500 RPM. Position controls for
maximum cooling and high blower. Insert thermometer in left register
and close all other ducts. With vehicle out of sun, close all windows
and doors. Connect pressure gauges and check readings.
3) If both gauges read too high, replace expansion valve. If
both read too low, recharge system after locating leak. If both
readings are normal, go to next step. If pressure side is too high and
suction side is normal, go to step 5). If pressure side is too low and
suction side is too high, go to step 6). If pressure side is normal
and suction side is too low, go to step 7).
4) Turn compressor off and observe gauges. If readings
equalize in 30 seconds, replace compressor. If readings take longer to
equalize, ensure capillary installation in evaporator is 7" (178 mm)
long on all models.
5) If installation is correct, run system at maximum cooling
for 15 minutes. If thermometer indicates temperature below 36øF (2øC)
when compressor is turned off, or temperature is above 48
øF (9øC) with
compressor on, replace temperature switch.
6) Check condenser fins and clean or straighten. If operation
is still not correct, discharge system, using approved refrigerant
recovery/recycling equipment, until bubbles show in sight glass.
Recharge until bubbles disappear, and recheck pressures. If still
incorrect, locate leaks and tighten fittings. Discharge system using
approved refrigerant recovery/recycling equipment. Evacuate to remove
all air and recharge system.
7) Check for bubbles at sight glass. If present, repair leaks
and recharge system. If no bubbles are present, check condenser-to-
expansion valve line for kinks and repair if necessary. Feel along
line from condenser to expansion valve. If there are no cold spots,
replace expansion valve.
8) If cold spot is felt, remove and flush out lines and
condenser. Check for bubbles at sight glass. If there are no bubbles
present, replace compressor. If bubbles are present, check for leaks.
Repair and recharge system.
INTERMITTENT COOLING
1) Ensure fan motor operates in all 4 speeds, air duct closes
off outside air and heater water valve is closed. Adjust belt tension
and clean condenser.
NOTE: If system doors allow air to leak by, evaporator will freeze
up and testing will no longer be possible.
2) Adjust engine speed to 2500 RPM. Set controls for maximum
cooling and high fan. Insert thermometer in left air duct and close
all other ducts. With vehicle under shade, close windows and doors and
connect pressure gauges. Operate system for 10 minutes.

E - THEORY/OPERATION - DIGIFANT
Article Text (p. 7)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:43PM
The idle air stabilizer valve is ECU controlled. On Vanagon
idle stabilizer valve is controlled by a separate idle stabilizer
controller. The idle air stabilizer operates to continuously maintains
engine idle at a computed engine idle speed.
IGNITION SYSTEM
The Hall Effect sending unit in the distributor, uses a
shutter window wheel mounted on the distributor shaft. The shutter
blades pass in and out of the air gap of the hall effect sender
resulting in signal pulses (engine speed signal). There is one shutter
window for each engine cylinder. Signals from distributor hall sender
are sent to the ECU.
ELECTRONIC IGNITION SYSTEM
IGNITION COIL CONTROL
Signals from distributor hall sender are sent to the ECU,
which produces a pulsating signal to the ignition coil. This computed
signal from ECU to ignition coil, control ignition timing according to
engine load (airflow sensor signal), engine speed (Hall Effect signal)
and engine coolant temperature.
IGNITION TIMING ADVANCE CONTROL SYSTEM
Timing is ECU controlled.
EMISSION SYSTEMS
EVAPORATIVE EMISSIONS SYSTEM
Fuel vapors are collected in the expansion tank. Any liquid
gasoline collect in expansion tank flows back to the fuel tank through
vent lines. See Fig. 4. Fuel vapors are drawn from tops of the
expansion tanks and flow into the carbon canister where the vapors are
stored. When the engine is not running.
After engine is started, the control valve is opened by
throttle vacuum. Fresh air is drawn into bottom of the canister. Fuel
vapors from the canister are drawn into the intake manifold.
EXHAUST GAS RECIRCULATION
Information is not available. See M - VACUUM DIAGRAMS for
system components and vacuum hose routings.

ELECTRICAL COMPONENT LOCATOR
Article Text (p. 18)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:44PMPower Window Relay In fuse/relay panel, below
left side of instrument panel.

ELECTRICAL COMPONENT LOCATOR
Article Text (p. 20)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:44PMRear Window Wiper Relay In fuse/relay panel, below
left side of instrument panel.

ELECTRICAL COMPONENT LOCATOR
Article Text (p. 24)
1990 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Thursday, March 23, 2000 09:44PMDoor Lock Control Unit Mounted on door lock
bi-pressure pump, behind trim
panel on right rear corner of
luggage compartment.Power Window Control Unit Behind trim panel on rear
pillar of left door.Rear Spoiler Control Unit Behind left of steering
column, near spoiler switch.Shoulder Belt Control Unit Behind trim panel on left door
rear pillar, on shoulder belt
motor.