Starter Motor - Ground Circuit Test
WARNING: This page is about a different car, the 2015 Lincoln MKS. 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
.
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 a remote starter switch between starter solenoid S-Terminal and the battery positive terminal.
- 2.
Connect the Digital 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 new battery cables. Refer to Battery, Mounting and Cables . 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 - 3.5L GTDI or Starter Motor - 3.7L Ti-VCT .