Safari Van M V6-262 4.3L VIN Z TBI (1990)
Hose/Line HVAC: Customer Interest
A/C Compressor - Noise
GMC NUMBER:
90-1B-53
GROUP:
1B Air Conditioning
DATE:
April, 1990
CORPORATE
NUMBER:
961206
SUBJECT:
AIR CONDITIONING COMPRESSOR NOISE DIAGNOSTICS
MODELS:
1990 M/L VANS EQUIPPED WITH FRONT AND/OR REAR AIR CONDITIONING (RPO C60 AND C69)
The 1990 M/L van air conditioning system is new. The new design provides improved air conditioning performance, reliability and quieter compressor
operation. The redesigned system consists of the following new items:
^
HE6 compressor, with cast accessory drive brackets and new pencil braces. The compressor has been relocated to the LH side of the engine.
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Refrigerant hose assemblies have revised routings, larger diameter suction hoses and a preformed discharge hose and muffler.
^
The condenser is thicker with openings added to the front body valance panel. Air duct is located below the bumper.
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Evaporator assembly is larger
^
The heater water control valve shuts off coolant flow to the heater when the temperature selector lever is positioned in full cold.
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Isolated attachments for auxiliary A/C system components:
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Underbody pipes
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Auxiliary evaporator module
The 1990 M van A/C system is designed to have a lower noise level than previous M van A/C systems. As in any system. a noise condition can be
experienced. If this should occur, it should be determined if it is A/C related.
A/C related noise can be determined by:
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Placing the transmission in neutral, blower in off position.
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Raising and lowering engine RPM's.
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Moving A/C lever between bi-level and vent. (This will cycle the A/C compressor on and off helping to "tune in" the noise. Make certain
compressor does not automatically cycle off).
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Noise present in A/C "on" cycle - add Pencil Brace Kit and follow "A/C Noise Diagnostic Chart" (Kit and Chart information found later in
bulletin).
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Noise present in A/C "off" cycle - condition is not the fault of the A/C system. If it is determined to be an A/C related noise, longer pencil
braces, Service Kit P/N 10118789, should be added to any 1990 M/L van manufactured prior to the following VIN numbers:
Chevrolet
1GNDM15Z8LB133267
GMC
1GDPM15Z6LB509694
Vehicles built prior to the above VIN numbers are equipped with shorter pencil braces. These should be changed to the longer pencil braces. Brace kit
installation instructions will be provided in the kit. Parts are currently available from GMSPO.
