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Hall Control Unit Test - 4000S

  1. Check ignition coil. See IGNITION COIL RESISTANCE CHECK - 4000S . Disconnect Hall control unit (in glove box) by pressing wire retaining clip. Set Digital Voltmeter (US 1119 ) on 20-volt scale. Connect voltmeter between terminals No. 2 and 4 at control unit connector.
  2. Turn ignition on. Voltmeter should indicate battery voltage. If reading is incorrect, find open circuit in wiring and repair as necessary. Connect voltmeter between terminals No. 4 and 6 at control unit connector.
  3. Crank engine and check signal from Hall Effect sending unit. Voltmeter should display some voltage. If voltage is displayed, check Hall Effect sending unit. See HALL EFFECT SENDING UNIT TEST - 4000S .
  4. If no voltage is displayed, turn ignition off and reconnect Hall control unit. Disconnect connector to Hall Effect sending unit at distributor. Connect voltmeter between negative terminal No. 1 and positive terminal No. 15 on ignition coil.
  5. Turn ignition on. Initial meter reading should be 2 volts minimum. Voltage must drop to zero after 1-2 seconds. If reading is incorrect, replace Hall control unit.
  6. Check ignition coil to see if any sealing compound has leaked out. Replace coil if necessary. Briefly tap center wire from disconnected Hall sending unit connector to ground.
  7. Displayed voltage must increase a minimum of 2 volts for a short time. If reading is incorrect, replace Hall control unit. Turn ignition off. Reconnect Hall Effect sending unit.
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