FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM
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Car repair manuals for everyone.
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Mercury
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1990
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Grand Marquis V8-351 5.8L
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Repair and Diagnosis
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Heating and Air Conditioning
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Testing and Inspection
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Symptom Related Diagnostic Procedures
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Electronic Climate Control
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Discharge Temperature Rises on Acceleration
Discharge Temperature Rises on Acceleration
Observe the servo vacuum under load. If it drops, an inoperative check valve or a vacuum leak exists. A severe leak will result in an air distribution shift to DEFROST.