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Starter Motor - Motor Feed Circuit

WARNING: This page is about a different car, the 2012 Ford Pickup, 2012 Ford F550 Super Duty, 2012 Ford F450 Super Duty, and 2012 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
  1. Make sure the battery is fully charged; carry out a battery load test. Refer to BATTERY, MOUNTING AND CABLES .
  2. Connect a remote starter switch between the starter solenoid S terminal and the battery positive (+) terminal.
  3. Connect the Fluke 77-IV Digital Multimeter positive lead to the battery positive (+) post. Connect the negative lead to the starter solenoid M terminal.
    Fig 1: Connecting Fluke 77-IV Digital Multimeter Positive Lead To Battery Positive Post
    G06126991Courtesy of FORD MOTOR CO.
    Item Part Number Description
    1 - S-terminal
    2 - Remote starter switch
    3 10653 Battery
    4 - Fluke 77-IV Digital Multimeter
    5 - B-terminal
    6 - M-terminal
  4. Engage the remote starter switch. Read and record the voltage. The voltage reading should be 0.5 volt or less.
  5. If the voltage reading is 0.5 volt or less, go to the STARTER MOTOR - GROUND CIRCUIT  component test.
  6. If the voltage reading is greater than 0.5 volt, this is an indication of excessive resistance in the connections, the positive battery cable or in the starter solenoid. Move the Fluke 77-IV Digital Multimeter negative lead to the starter solenoid B terminal and repeat the test. If the voltage reading at the B terminal is lower than 0.5 volt, the concern is either in the connections at the starter solenoid or in the solenoid contacts.
    Fig 2: Connecting Fluke 77-IV Digital Multimeter Negative Lead To Starter Solenoid B Terminal
    G06126992Courtesy of FORD MOTOR CO.
    Item Part Number Description
    1 - S-terminal
    2 - Remote starter switch
    3 10653 Battery
    4 - Fluke 77-IV Digital Multimeter
    5 - B-terminal
    6 - M-terminal
  7. Remove the cables from solenoid B, S and M terminals. Clean the cables and connections and reinstall the cables to the correct terminals. Repeat Steps  3 through  6. If the voltage drop reading is still greater than 0.5 volt when checked at the M terminal and less than 0.5 volt when checked at the B terminal, the concern is in the solenoid contacts. Install a new starter motor.
  8. If the voltage reading taken at the solenoid B terminal is still greater than 0.5 volt after cleaning the cables and connections at the solenoid, the concern is either in the positive (+) battery cable connection or in the positive battery cable itself.
  9. Clean the positive (+) battery cable connection. If this does not solve the problem, install a new positive battery cable.