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mulator, the powertrain control module (PCM) in the The A/C compressor clutch components cannot be repaired and, if faulty or damaged, they must be DIAGNOSIS AND TESTING A/C COMPRESSOR CLUTCH COIL The A/C compressor clutch coil electrical circuit is controlled by the powertrain control module (PCM) PRELIMINARY CHECKS (1) If the compressor clutch will not engage, verify the refrigerant charge level (Refer to 24 - HEATING (2) If the A/C compressor clutch still will not engage, disconnect the wire harness connector for the COIL RESISTANCE TEST (1) Disconnect and isolate the negative battery cable. (2) Disconnect the wire harness connector from the A/C clutch field coil lead connector. (3) Use an ohm meter and measure the resistance of the clutch coil at the coil lead connector terminals. (4) Refer to the A/C Clutch Coil Specifications chart for the acceptable A/C clutch coil resistance. (a) If the A/C clutch coil reading is below speci- fications, the coil is shorted and must be replaced. (b) If the A/C clutch coil reading is above speci- fications, the coil is open and must be replaced. COIL CURRENT DRAW TEST (1) Verify the battery state of charge (Refer to 8 - ELECTRICAL/BATTERY SYSTEM/BATTERY - DIAGNOSIS AND TESTING). (2) Connect an ammeter (0 to 10 ampere scale selected) in series with the clutch coil feed terminal. (3) With the A/C-heater control in the A/C mode and the blower motor at low speed, start the engine (4) The A/C compressor clutch should engage immediately, and the clutch coil supply voltage (5) Refer to the A/C Clutch Coil Specifications chart for the acceptable A/C clutch coil current draw. (a) If the A/C clutch coil current reading is zero, the coil is open and must be replaced. (b) If the A/C clutch coil current reading is above specifications, the coil is shorted and must be Fig. 1 A/C Compressor Clutch 1 - BOLT 24 - 10 CONTROLS ZB A/C COMPRESSOR CLUTCH (Continued) |