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Speed Sensor Check

  1. Obtain a Fresnel lens front LED from an electronics store or use Special Test Unit (171 919 061B). Connect a 220 ohm-1/4 watt resistor in series with one of the LED terminals.
  2. Connect positive LED test lead to terminal No. 8 of CU harness connector. Connect negative LED test lead to terminal No. 27 of same connector. Disconnect and ground coil wire. Crank engine. LED will flicker dimly if speed sensor is sending a signal.