Starter Motor - Ground Circuit Test
WARNING: This page is about a different car, the 2017 Lincoln Navigator and 2017 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:
Before beginning any service procedure, refer to Safety Warnings in Service Information
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.
- 1.
Connect a remote starter switch between starter solenoid "S" terminal and the battery positive terminal.
- 2.
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.
- 4.
Engage the remote starter switch and crank the engine. Read and record the voltage reading. The reading should be 0.5 volt or less.
- 5.
If the voltage drop is greater than 0.5 volt, clean the negative cable connections at the battery, the body ground connections and the starter ground connection. Retest.
- 6.
If the voltage drop is greater than 0.5 volt, install a new negative battery cable. Refer to Battery, Mounting and Cables .
- 7.
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 .