Starter Motor - Ground Circuit Test
WARNING: This page is about a different car, the 2020 Ford F-150. 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. 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 - 3.0L Power Stroke Diesel .
- 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 .