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Home >> GMC >> 1991 >> Value Van 7.4 N >> Repair and Diagnosis >> External Pages >> Different car >> Section 4 (Engine Controls - System/Component Tests) >> Miscellaneous ECM Controls >> Chart C-10, A/C Clutch Control Diagnosis (A/T) (2 Of 2) 4.3L Turbo PFI >> Notes

Chart C-10, A/C Clutch Control Diagnosis (A/T) (2 Of 2) 4.3L Turbo PFI: Notes

WARNING: This page does not describe the selected car, but rather 35 other vehicles, including the 1992 Pontiac Trans Sport, 1992 Oldsmobile Silhouette, 1992 Oldsmobile Bravada, 1992 GMC Yukon, and 1992 GMC Vandura Special. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Test numbers refer to test numbers on diagnostic charts.
  1. 3)  Checks for faulty cycling switch. Solenoids and relays are turned on and off by the ECM, using "drivers". Each driver is a part of a group of 4, called quad-drivers. Failure of one driver can damage any other driver in the set. Solenoid and relay coil resistance should be greater than 20 ohms.