Shorts to Power
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2005 Mercury Sable, 2005 Mercury Mountaineer, 2005 Mercury Monterey, 2005 Mercury Montego, and 2005 Mercury Mariner. However, it is still accessible from the selected car via links, so may be relevant.
Key on to power up the circuit. Measure the voltage between the suspect circuit at the harness connector and a reliable ground. The voltage must be less than 1.0 volt.