Saab 900 Service Manual page 49

Heating and ventilation system, air conditioning system 854-37
VIR system
The system does not cool at all
First:
- Cheek the belt tension.
- Start the engine. Set the idling speed at 2500 r.p.m.
- Set the air distribution control at AC max.
- Check that air is evacuated from the panel vents.
- Check that the compressor switch turns on and off when the
air distribution control is turned from AC max. to 0 and back.
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Switch does not work.
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Switch works. 1
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Check voltage at connection B of the fuse.
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Faulty compressor. Replace faulty part.
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No voltage. Voltage present.
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Check voltage supply Check voltage at con-
H
Voltage present
for fault using wiring neetion L of the fuse
diagram page.
Check compressor switch
No voltage wiring.
Fuse blown
Wiring correct.
Defective compressor switch
Insufficient or no refrigerant in the system:
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Fill the system. See page
854-38
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Locate and seal leak.
- Replace fuse.
- Start engine and check fuse.
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Fuse blown
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Fuse whole I
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- Stop engine.
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. - Check that wire S on the fuse
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Earths
is earthing.
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Check wire between the compres-
Does not earth.
sor and c()nnection S for damage.
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Expansion and suction throttling
Wire damaged
Wire undamaged
valve sticking.
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- Clean and replace defective
valve
Repair or replace
Replace compressor
- Replace fuse.
cable network
switch
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Replace fuse I
Saab 900
::-
.
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