Starter Motor - Ground Circuit

2009 Mercury Milan Premier, 3.0 1, AWDSECTION Starter Motor - Ground Circuit
WARNING: This page is about a different car, the 2006 Mercury Milan, 2006 Lincoln Zephyr, and 2006 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

A slow cranking condition can be caused by resistance in the ground or return portion of the cranking circuit. Check the voltage drop in the ground circuit as follows:

  1. Connect the 73III Automotive Meter positive lead to the starter motor housing (the connection must be clean and free of rust or grease). Connect the negative lead to the negative (-) battery terminal.
    Fig 1: Checking Voltage Drop In Ground Circuit
    G04681320Courtesy of FORD MOTOR CO.
  2. Engage the remote starter switch and crank the engine. Read and record the voltage reading. The reading should be 0.5 volt or less.
  3. If the voltage is more than 0.5 volt, clean the negative cable connections at the battery, the body ground connections and the starter ground connections. Retest.
  4. If the voltage is more than 0.5 volt, install a new cable. If the voltage reading is less than 0.5 volt and the engine still cranks slowly, install a new starter motor.
RENDER: 1.0x

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