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Home >> BMW >> 1997 >> 328is Automatic >> Repair and Diagnosis >> Electrical >> Charging Systems >> Generator & Regulator >> On-Vehicle Testing >> Unloader Relay >> Except 3-Series
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Except 3-Series

  1. Check charging system fuse No. 28. Replace fuse if necessary. Remove unloader relay. Turn ignition on. On 5-series, check for battery voltage at relay socket terminals No. 5 and 8 (Green/White wires). On 7-series, check for battery voltage at relay socket terminals No. 4 and 5 (Green/White wires). On all models, if battery voltage is present, go to next step. If battery voltage is not present, repair circuits.
  2. Ensure relay socket terminal No. 2 (Brown/Black wire) is grounded. If socket terminal is grounded, go to next step. If socket terminal is not grounded, repair ground circuit.
  3. Start engine and ensure charge indicator light goes out. If charge indicator light remains on, check charging system. If charge indicator light goes out, go to next step.
  4. With engine running, ensure a minimum of 12 volts exists at relay socket terminal No. 4 (5-series) or terminal No. 8 (7-series). If voltage is as specified, go to next step to check voltage to accessories. If voltage is not as specified, repair wire to generator.
  5. Turn ignition switch off. Connect a fused jumper wire between relay socket terminals No. 5 (Green/White wire) and No. 6 (Red wire). Turn ignition on. Ensure battery voltage is supplied to relay operated systems (i.e., rear defogger relay, heated seats, automatic A/C, etc.). If voltage is not present to these systems, repair circuits. If voltage is present to these systems, go to next step.
  6. Install unloader relay. Start engine and ensure battery voltage is present at relay operated systems. If relay does not work, replace unloader relay.
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