Ford 2003 Explorer Owner's Manual page 141

3. Connect the negative (-) cable to the negative (-) terminal of the
assisting battery.
4. Make the final connection of the negative (-) cable to an exposed
metal part of the stalled vehicle's engine, away from the battery and the
carburetor/fuel injection system. Do not use fuel lines, engine rocker
covers or the intake manifold as grounding points.
Do not connect the end of the second cable to the negative (-)
terminal of the battery to be jumped. A spark may cause an
explosion of the gases that surround the battery.
5. Ensure that the cables are clear of fan blades, belts, moving parts of
both engines, or any fuel delivery system parts.
Roadside Emergencies
141