Component Test(s)
WARNING: This page is about a different variant/trim than selected.
Starter Motor - Positive Circuit Test
NOTE:
Always make the multimeter connection at the component terminal rather than at the wiring end of the connector. Making a connection at the wiring end of the connector could result in false readings because the meter will not pick up a high resistance between the wiring connector and component.
- Make sure the battery is fully charged. REFER to: Battery
- Perform a battery drain test. REFER to: Battery Drain Check
- Connect a remote starter switch between starter solenoid "S" terminal and the battery positive terminal.
- Connect the multimeter positive lead to the battery positive post. Connect the negative lead to the starter solenoid "M" terminal.
- Place gear selector lever in Park or Neutral.
- Engage the remote starter switch. Read and record the voltage. The voltage reading should be 0.5 volt or less.
- If the voltage reading is 0.5 volt or less, perform Starter Motor - Ground Circuit Test refer to Component Test(s) .
- A voltage reading greater than 0.5 volt is an indication of excessive resistance in the connections, the positive battery cable or in the starter solenoid. Remove the cables from the 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 reading is still greater than 0.5 volt when checked at the "M" terminal, move the multimeter negative lead to the starter solenoid "B" terminal.
- With the gear selector lever in Park or Neutral, engage the remote starter switch. Read and record the voltage.
- If the voltage reading at the "B" terminal is lower than 0.5 volt, the concern is in the connections at the starter solenoid or in the solenoid contacts. Install a new starter motor. REFER to: Starter Motor
- If the voltage reading taken at the solenoid "B" terminal is greater than 0.5 volt after cleaning the cables and connections at the solenoid, the concern is in the positive battery cable connection or in the positive battery cable itself. Clean the positive battery cable connection. If this does not resolve the concern, install a new positive battery cable. REFER to: Battery Cables - 2.7L EcoBoost (238kW/324PS)
Starter Motor - Ground Circuit Test
A slow cranking condition can be caused by resistance in the ground or return portion of the cranking circuit. This procedure checks the voltage drop in the ground circuit.
- Connect a remote starter switch between starter solenoid "S" terminal and the battery positive terminal.
- Connect the multimeter 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.
- Place gear selector lever in Park or Neutral.
- Engage the remote starter switch and crank the engine. Read and record the voltage reading. The reading should be 0.5 volt or less.
- If the voltage reading is greater than 0.5 volt, clean the negative cable connections at the battery, the body ground connections and the starter ground connection. Retest.
- If the voltage reading is greater than 0.5 volt, install a new negative battery cable. REFER to: Battery Cables - 2.7L EcoBoost (238kW/324PS)
- If the voltage reading is less than 0.5 volt and the engine still cranks slowly, install a new starter motor. REFER to: Starter Motor