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System Check

  1. Start engine and warm to normal operating temperature. Air pump clutch should be disengaged and pump should be stopped.
  2. Disconnect plug from coolant switch and insert jumper wire into connector terminals. Turn ignition switch "OFF" and then to the "ON" position without starting engine. Clutch and switch-over valve should operate.
  3. Using volt/ohmmeter, connect negative lead to terminal 3 of diagnostic plug (on fenderwell). Connect positive lead of volt/ohmmeter to battery. With engine running at operating temperature, voltage should be present. Mark volt/ohmmeter dial to indicate needle position, then stop engine.
  4. Remove connector from magnetic clutch on air pump. Use jumper wires to connect clutch terminals to ground and battery voltage. Start engine and observe volt/ohmmeter.
  5. Reading should be as previously marked. Disconnect vacuum lines from switch-over valve and connect them together. Volt/ohmmeter reading should increase. If not, proceed to component testing.
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