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Home >> Oldsmobile >> 1994 >> Ninety-Eight Regency >> Repair and Diagnosis >> External Pages >> Different car >> Section 20 (Engine Controls - System/Component Tests) >> Engine Sensors & Switches >> Engine Controls - System/Component Tests >> A/C ON (A/C Request) Switch Test
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A/C ON (A/C Request) Switch Test

WARNING: This page is about a different car, the 1994 Pontiac Bonneville, 1994 Oldsmobile Eighty-Eight, and 1994 Buick LeSabre. However, it is still accessible from the selected car via links, so may be relevant.
  1. Start engine and allow to idle. If a scan tester is available, scan A/C request parameter. Move A/C mode selector back and forth between ON and OFF positions. Scan status should change.
  2. If scan tester is not available or scan status does not change, measure voltage between ground and ECM A/C request terminal. For wiring schematics, see mini-schematics under A/C CLUTCH (C-10) & ELECTRIC COOLING FAN (C-12) under MISCELLANEOUS CONTROLS  .
  3. With A/C mode selector in the ON position, battery voltage should be present. If battery voltage is not present, check for open between A/C mode select switch and ECM A/C request terminal, low A/C refrigerant level causing low pressure switch to open, bad A/C fuse or bad A/C mode select switch.
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