The easiest way to troubleshoot a starter solenoid on a Ford Explorer is to eliminate the use of the Explorer’s battery and start the vehicle right from the starter. To do this, you have to put auxiliary power to the starter with a pair of jumper cables and a known working vehicle. This process tells you if the starter is defective or if the battery or cabling is defective.
Place the Ford Explorer onto a set of front-end ramps and secure the parking break. If the Ranger has a suspension lift kit installed and the underneath of the vehicle is accessible without driving onto ramps, skip this step.
Disconnect the negative battery cable from the battery. Disconnect the positive battery cable from the battery. Lift the battery out of the vehicle and place it off to the side. This prevents the cables from accidentally touching the battery terminals while you work on the Explorer.
Locate the starter under the Explorer on the driver side of the vehicle. It is a long cylindrical tube connected to the engine block. It is approximately 8 inches in length with two large wires extending from it.
Place the red battery jumper cable on the positive wire connector located on the back of the starter. Double-check that the wire that extends from the wire connector goes to the positive battery cable. Place the ground battery jumper cable onto the chassis of the vehicle.
Place the other end of the positive battery jumper cable onto the positive terminal of a working vehicle. Place the ground battery jumper cable onto the negative battery terminal of the working vehicle.
Attempt to start the Explorer. If it starts, the issue is with the battery or cabling that extend to the starter solenoid. If the Explorer still fails to turn over or crank, the issue is with the starter and it requires replacement.
